United States v. Sullivan

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FOR PUBLICATION

UNITED STATES COURT OF APPEALS
FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA, No. 23-927
D.C. No.
Plaintiff - Appellee,
3:20-cr-00337-
WHO-1
v.

JOSEPH SULLIVAN, ORDER AND
AMENDED
Defendant - Appellant. OPINION

Appeal from the United States District Court
for the Northern District of California
William Horsley Orrick, District Judge, Presiding

Argued and Submitted October 8, 2024
San Francisco, California

Filed March 13, 2025
Amended November 12, 2025

Before: M. Margaret McKeown, Anthony D. Johnstone,
and Ana de Alba, Circuit Judges.

Order;
Opinion by Judge McKeown
2 USA V. SULLIVAN

SUMMARY *

Criminal Law

The panel filed (1) an order amending its March 13,
2025, opinion and denying a petition for rehearing en banc;
and (2) an amended opinion affirming Joseph Sullivan’s jury
conviction for obstruction of justice and misprision of a
felony arising from his efforts, while the Chief Security
Officer for Uber Technologies, to cover up a major data
breach even as Uber underwent investigation by the Federal
Trade Commission into the company’s data security
practices.
Sullivan argued that the district court erred in rejecting
two of his proposed jury instructions regarding the
obstruction charge.
• The panel held that United States v. Bhagat,
436 F.3d
1140
(9th Cir. 2006), forecloses Sullivan’s argument
that the district court erred by rejecting an instruction
that would have required the jury to find that there
was a “nexus” between his conduct and the pending
FTC proceeding. The panel explained that Supreme
Court cases cited by Sullivan are not clearly
irreconcilable with Bhagat.
• Regarding Sullivan’s contention that the district
court erred by rejecting his “duty to disclose”
instruction, the panel held that any error was
harmless beyond a reasonable doubt. Sullivan

*
This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
USA V. SULLIVAN 3

argued that, because this proposed instruction was
not given, the jury may have convicted on a theory—
inaction by a defendant under no duty to disclose—
that was invalid under
18 U.S.C. § 1505
, and that the
verdict must be set aside because it is impossible to
tell which ground the jury selected. The panel
concluded that there is no reasonable possibility that
the jury rested its conviction on the § 1505 charge
based only on the claimed invalid theory and not also
on a concededly valid causing-to-be-done theory,
which rests on
18 U.S.C. § 2
(b). The panel therefore
did not need to reach the question of validity under
§ 1505.
Sullivan argued that the evidence of his alleged
misprision was insufficient as a matter of law. Misprision is
the crime of “having knowledge of the actual commission of
a felony” and “conceal[ing]” or failing to “as soon as
possible make known the same to some judge or other person
in civil or military authority under the United States.” To
establish misprision, the government is obliged to show that
the principal committed and completed the felony
alleged. Here, that meant proving that hackers had
intentionally accessed Uber’s computers without
authorization and thereby obtained information from those
protected computers, in violation of the Computer Fraud and
Abuse Act (CFAA).
• The panel held that the hackers’ illegal conduct could
not be laundered through Uber’s post hoc
authorization, via a non-disclosure agreement
(NDA), of their computer access.
• The panel held that the evidence does not support
Sullivan’s claim that, even if the hackers were
4 USA V. SULLIVAN

unauthorized within the meaning of the CFAA, he
reasonably believed that the NDA cleansed the
felonious access of its illegality.
• The panel held that a rational jury could have found
that Sullivan, who had been an Assistant U.S.
Attorney in a “Computer Hacking and IP Unit,”
knew that the conduct in question was a felony
punishable by more than a year in prison.
The panel held that the district court did not abuse its
discretion in permitting the introduction of the guilty plea
agreement signed by one of the hackers. Any unfair
prejudice did not substantially outweigh the probative value.

COUNSEL

Ross D. Mazer (argued) and Andrew F. Dawson, Assistant
United States Attorneys; Merry Jean Chan, Chief, Appellate
Section, Criminal Division; Matthew M. Yelovich, Attorney
for the United States Acting Under Authority Conferred by
28 U.S.C. § 515
; Craig H. Missakian, United States
Attorney; Office of the United States Attorney, United States
Department of Justice, San Francisco, California; for
Plaintiff-Appellee.
Christopher J. Cariello (argued) and Eliza Lehner, Orrick
Herrington & Sutcliffe LLP, New York, New York; Aravind
Swaminathan, Orrick Herrington & Sutcliffe LLP, Seattle,
Washington; Amari L. Hammonds, Orrick Herrington &
Sutcliffe LLP, Los Angeles, California; for Defendant-
Appellant.
USA V. SULLIVAN 5

Jeffrey R. Babbin and Nathan J. Guevremont, Wiggin &
Dana LLP, New Haven, Connecticut; Anjali Dalal, Wiggin
and Dana LLP, New York, New York; Gia L. Cincone,
NACDL Amicus Committee, San Francisco, California; for
Amici Curiae National Association of Criminal Defense
Lawyers and Due Process Institute.
Nathan R. Morales, Stoel Rives LLP, Portland, Oregon;
Matthew D. Segal, Stoel Rives LLP, Sacramento, California;
for Amici Curiae Cloud Security Alliance and Security
Innovation Network.

ORDER

The opinion filed March 13, 2025, is hereby amended.
The amended opinion will be filed concurrently with this
order. Judge Johnstone and Judge de Alba have voted to
deny the petition for rehearing en banc, and Judge McKeown
has so recommended. The petition for rehearing en banc is
DENIED. Dkt. No. 92. No future petitions for rehearing or
rehearing en banc will be entertained.
IT IS SO ORDERED.
6 USA V. SULLIVAN

OPINION

McKEOWN, Circuit Judge:

Cybersecurity has become a major preoccupation of
businesses as network hacks and data breaches multiply.
Companies now turn to seasoned experts to address these
challenges. Among the ranks of these experts is Joseph
Sullivan, who served as the Chief Security Officer (“CSO”)
for Uber Technologies (“Uber”) from 2015 to 2017. When
he began at Uber, Sullivan’s reputation was that of a “world-
class” cybersecurity expert, with a stint as an Assistant U.S.
Attorney and several years of private-sector leadership
experience under his belt. This case arose from choices
Sullivan made as Uber’s CSO in the wake of a major data
breach—specifically, his efforts to cover up that breach,
even as Uber underwent investigation by the Federal Trade
Commission (“FTC”) into the company’s data security
practices.
When the breach and its cover-up came to light after
having remained hidden for over a year, the government
brought criminal charges against Sullivan. A jury convicted
him of obstruction of justice and misprision of a felony. On
appeal, Sullivan challenges several jury instructions, the
sufficiency of the evidence, and an evidentiary ruling. We
affirm.
Background
In 2014, Uber experienced a data breach. A hacker
discovered an Amazon Web Services (AWS) “key”—a type
of log-in—embedded in code displayed publicly on GitHub,
a platform on which developers store and sometimes share
code. The hacker used the key to access the troves of data
USA V. SULLIVAN 7

that Uber stored privately on AWS. From the AWS database,
the hacker downloaded sensitive information pertaining to
tens of thousands of Uber drivers.
Shortly after this breach became public, the FTC
commenced an investigation into Uber’s data security
practices, including its storage of rider and driver
information on AWS and the company’s “alleged deceptive
statements” about those practices.
In 2015, Uber hired Sullivan as its CSO. In August 2016,
Sullivan took on the additional title of Deputy General
Counsel. By then, Sullivan was very involved in Uber’s
response to the FTC’s ongoing investigation: He made a
presentation to FTC staff on Uber’s data security program,
and he testified before the Commission in an investigational
hearing, including on Uber’s practices of data encryption. He
also supervised the preparation of at least two of Uber’s
official statements to the FTC.
Another data breach occurred in October 2016. Hackers
gained access to Uber’s private account on GitHub—the
same platform as in the 2014 attack. Embedded in the code
stored in that account, the hackers found AWS keys—the
same types of keys, discovered in a similar way, as in the
2014 attack. The hackers used the keys to access Uber’s
AWS datastore and download the names and driver’s license
numbers of some 600,000 individuals—the same type of
breach on the same infrastructure, at an even larger scale, as
in the 2014 attack. The downloaded data was unencrypted.
Despite the similarities between the 2016 incident and
the 2014 incident that the FTC was already investigating, no
one at Uber informed the FTC of this new breach. Instead,
unbeknownst to federal officials, Sullivan and a group of
Uber staffers decided to track down the hackers and pressure
8 USA V. SULLIVAN

them into signing a non-disclosure agreement (“NDA”) that
purported to re-characterize the hack as “research” into
“vulnerabilities” under Uber’s Bug Bounty Program.
Through bug bounty programs, companies solicit and
reward external security researchers’ discovery and
disclosure of their systems’ vulnerabilities. See Jasmine
Arooni, Debugging the System: Reforming Vulnerability
Disclosure Programs in the Private Sector,
73 Fed. Comm.
L.J. 443
, 448–50 (2021). In ostensible exercise of the Bug
Bounty Program, Uber paid the hackers $100,000 in
exchange for their signatures on an NDA and an agreement
to delete the downloaded data. Sullivan was involved in
drafting the NDA and ultimately informed Travis Kalanick,
then Uber’s Chief Executive Officer, that the hackers had
signed the “contract.” 1 Sullivan did not inform Uber’s
general counsel of these developments, despite telling other
employees to the contrary.
Sullivan also did not correct old statements, and instead
signed off on new statements, to the FTC that Uber’s stores
of private data on AWS were encrypted, even though the
breach had exposed the fact that some of this data was
unencrypted. Sullivan did so despite his and his team’s
awareness that he “was just deposed on this specific topic”
and that news of the breach would “play very badly based on
previous assertions” to the FTC about data encryption. In the
fall of 2017, Uber hired a new CEO, Dara Khosrowshahi.
Soon after, Sullivan informed Khosrowshahi of the hack, but
he omitted and misrepresented key details: He falsely stated
that no data had been downloaded; mischaracterized the

1
The NDAs were initially signed with the hackers’ pseudonyms. After
further investigation by Uber, the agreements were subsequently re-
signed with the hackers’ real names.
USA V. SULLIVAN 9

timing of the payment to the hackers; and omitted the
magnitude of the breach and the amount of money paid to
resolve it. When Khosrowshahi discovered the truth, he fired
Sullivan and publicly disclosed the breach.
Upon learning of the breach, the FTC revised its
complaint against Uber, withdrew acceptance of its original
consent agreement with Uber, and prepared a new consent
agreement that would impose additional reporting
obligations on Uber. The revised complaint specifically
referenced the 2016 data breach and the state of Uber’s data
security as of November 2016.
Meanwhile, federal prosecutors brought felony charges
against one of the hackers, Vasile Mereacre, for violating the
Computer Fraud and Abuse Act (“CFAA”),
18 U.S.C.
§ 1030
. In 2019, Mereacre pled guilty. Criminal charges
were also brought against Sullivan. Sullivan was then tried
and convicted for obstruction of justice and misprision of a
felony. After sentencing, Sullivan moved for a judgment of
acquittal or a new trial on the grounds that the district court
erred in formulating the jury instructions and in admitting
Mereacre’s guilty plea into evidence; and that the evidence
of his conviction was insufficient as a matter of law. The
court denied his motion. We have jurisdiction under
28
U.S.C. § 1291
.
Analysis
I. The Jury Instructions—Obstruction Conviction
Sullivan claims error with respect to two of his proposed
jury instructions regarding the obstruction conviction—the
“nexus” instruction and the “duty to disclose” instruction.
10 USA V. SULLIVAN

A. Nexus Instruction
We review de novo the district court’s rejection of
Sullivan’s proposed “nexus” instruction, which would have
required the jury to find that “there was a nexus between the
defendant’s conduct and the pending FTC proceeding.” 2
United States v. Munoz,
412 F.3d 1043, 1046
(9th Cir. 2005)
(reviewing de novo a claim that “a jury instruction misstated
an element of the charged offense”). The proposed
instruction did not define “nexus.”
Section 1505 provides that “[w]hoever corruptly, or by
threats or force, or by any threatening letter or
communication influences, obstructs, or impedes or
endeavors to influence, obstruct, or impede the due and
proper administration of the law under which any pending
proceeding is being had before any department or agency of
the United States . . . [s]hall be fined under this title,
imprisoned not more than 5 years or, if the offense involves
international or domestic terrorism (as defined in [S]ection
2331), imprisoned not more than 8 years, or both.”
18 U.S.C.
§ 1505
.
In accord with the statutory language, the jurors were
instructed: “For the defendant to be found guilty [under
Section 1505], the government must prove each of the
following elements beyond a reasonable doubt: First, there
was a proceeding pending before a department or agency of
the United States; Second, the defendant was aware of the
proceeding; and Third, the defendant intentionally

2
After some back-and-forth, the parties ultimately agreed that a Section
1505 conviction necessitates a finding of a nexus between the allegedly
obstructive conduct and the pending proceeding. They continue to
disagree as to whether an additional instruction as to a nexus finding was
required.
USA V. SULLIVAN 11

endeavored corruptly to influence, obstruct, or impede the
pending proceeding.” This instruction precisely mirrors the
elements of Section 1505, as spelled out in United States v.
Price,
951 F.2d 1028, 1031
(9th Cir. 1991) (“First, there
must be a proceeding pending before a department or agency
of the United States. Second, the defendant must be aware of
the pending proceeding. Third, the defendant must have
intentionally endeavored corruptly to influence, obstruct or
impede the pending proceeding.” (citations omitted)).
Ninth Circuit precedent forecloses Sullivan’s argument.
We held in United States v. Bhagat that there is no “need to
supplement the Price instructions with additional elements,”
including a “nexus” element, for a conviction under Section
1505.
436 F.3d 1140, 1148
(9th Cir. 2006).
Sullivan’s counsel candidly acknowledged: “the Ninth
Circuit has held in a [Section] 1505 case that Aguilar’s nexus
requirement did not require a separate jury instruction to that
effect.” Sullivan asks us to overrule Bhagat, claiming that
we have authority to do so because the case is “clearly
irreconcilable” with intervening Supreme Court precedent.
Miller v. Gammie,
335 F.3d 889, 900
(9th Cir. 2003) (en
banc). Sullivan cites three cases that he construes as
irreconcilable: United States v. Aguilar,
515 U.S. 593
(1995); Arthur Andersen LLP v. United States,
544 U.S. 696
(2005); and Marinello v. United States,
584 U.S. 1
(2018).
Although these cases support either a “nexus”
requirement or “nexus” instruction in their respective
contexts, none is clearly irreconcilable with Bhagat. To
begin, none of the cases concerns Section 1505. And, in each
case, the statutes, facts, or jury instructions created
ambiguities that called for clarification as to the existence of
a “nexus.” No such ambiguities exist in Bhagat or here.
12 USA V. SULLIVAN

The Section 1503 charge in Aguilar involved a
defendant’s statement in an investigation that was
“ancillary” to the proceeding covered by the statute. Aguilar,
515 U.S. at 599–601. The attenuation in the relationship
between Aguilar’s act and the covered proceeding
necessitated the Court’s clarification of Section 1503’s
implicit “nexus” requirement. Id. at 599. The Court in
Aguilar explicitly did not address jury instructions. Id. at
606.
Nor are the other cases cited by Sullivan irreconcilable
with Bhagat. In Marinello the prosecution was brought
under the Omnibus Clause of Section 7212(a) of the Internal
Revenue Code.
26 U.S.C. § 7212
(a). That provision does not
refer to a “proceeding,” but only to “the due administration
of [the Internal Revenue Code].”
26 U.S.C. § 7212
(a). The
district court “did not instruct the jury that it must find that
Marinello knew he was under investigation and intended
corruptly to interfere with that investigation.” Marinello,
584 U.S. at 5
. Given the statute’s silence and the lack of jury
instruction as to either the defendant’s awareness of, or
intended effect upon, any investigation, the Court clarified
that the Omnibus Clause requires instruction that the
government must show a “‘nexus’ between the defendant’s
conduct and a particular administrative proceeding.”
Id. at
13
. Even if Arthur Andersen is intervening authority, and we
are dubious that it is, the jury instructions in that Section
1512 case erroneously conveyed that the defendant need not
even have “ha[d] in contemplation any particular official
proceeding.”
544 U.S. at 708
.
The text of Section 1505, the wording of the Price
instructions, and the factual relevance of only one
proceeding distinguish Bhagat from Aguilar, Marinello, and
Arthur Andersen. Like Bhagat, this case involved only one
USA V. SULLIVAN 13

proceeding, of which the defendant was undisputedly aware.
Under Bhagat, the Price elements require a nexus by
implication, and no other jury instruction given here
undermined or contradicted that implication. Sullivan was
not entitled to an additional instruction that “merely
duplicates” what the jury had already been told. United
States v. Lopez-Alvarez,
970 F.2d 583, 597
(9th Cir. 1992).
Consistent with Bhagat, we conclude that nothing more was
needed. The district court did not err in declining to give
Sullivan’s proposed instruction. 3 Finding no error, we
decline to reach the question of harmlessness.
B. The “Duty to Disclose” Instruction
Sullivan also claims that the district court erred by
rejecting his proposed “duty to disclose” instruction: that, if
the basis of the obstruction-of-justice conviction was
Sullivan’s “withholding of information, the government
must prove beyond a reasonable doubt that [he] had a duty
to disclose that information to the FTC.” Sullivan contends
that, because this proposed instruction was not given, the
jury may have convicted on a theory that was invalid under
Section 1505—that is, inaction by a defendant under no duty
to disclose. He urges application of the Yates rule that “a
verdict [is required] to be set aside in cases where the verdict
is supportable on one ground, but not on another, and it is
impossible to tell which ground the jury selected.” Yates v.

3
Embedded in Sullivan’s arguments regarding the jury instructions is a
challenge to the sufficiency of the evidence as to obstruction, based on a
lack of nexus. Viewing the evidence in the light most favorable to the
prosecution, we conclude that a “rational trier of fact” could have found
that there was a nexus between Sullivan’s choices and the FTC
proceeding, Coleman v. Johnson,
566 U.S. 650, 654
(2012), whether
“nexus” is defined as “natural and probable effect” or as a “relationship
in time, causation, or logic.” Aguilar,
515 U.S. at 599
.
14 USA V. SULLIVAN

United States,
354 U.S. 298, 312
(1957), overruled on other
grounds by Burks v. United States,
437 U.S. 1
(1978).
We need not resolve this issue. Even assuming that the
instruction should have been given and that the error
implicates the Yates rule, it is well settled that “errors of the
Yates variety are subject to harmless-error analysis.” Skilling
v. United States,
561 U.S. 358
, 414 (2010). A Yates error is
harmless “if, after a ‘thorough examination of the record,’
we are able to ‘conclude beyond a reasonable doubt that the
jury verdict would have been the same absent the error.’”
United States v. Galecki,
89 F.4th 713, 741
(9th Cir. 2023)
(quoting Neder v. United States,
527 U.S. 1, 19
(1999)).
After carefully examining the trial record, we conclude that
any such error was harmless beyond a reasonable doubt.
The premise of Sullivan’s Yates argument is that the
jurors were permitted to convict him of violating
Section 1505 based either (1) on the claimed invalid theory
that he personally withheld information, even though he
himself had no duty to disclose it to the FTC; or (2) on the
theory that he caused Uber, which concededly did have a
duty to disclose, to fail to provide this information to the
FTC. There is no dispute that the latter theory, which rests
on
18 U.S.C. § 2
(b), 4 is legally valid under our court’s
decision in United States v. Singh,
979 F.3d 697
, 717–18 (9th
Cir. 2020) (concluding that the defendant need not have a

4
Section 2(b) states: “[w]hoever willfully causes an act to be done which
if directly performed by him or another would be an offense against the
United States, is punishable as a principal.”
18 U.S.C. § 2
(b). “[U]nder
[Section] 2(b), a defendant may be convicted, even if he did not commit
all the elements of the offense . . . .” United States v. Ubaldo,
859 F.3d
690, 702
(9th Cir. 2017). In this context, Section 2(b) “is considered
embodied in full in every federal indictment.” United States v. Michaels,
796 F.2d 1112, 1118
(9th Cir. 1986).
USA V. SULLIVAN 15

duty to disclose, so long as the third party whom he causes
not to make the disclosure does have such a duty). On this
particular record, “there is no reasonable possibility that the
jury here rested its conviction[]” on the Section 1505 charge
based only on the claimed invalid theory and not also on the
concededly valid causing-to-be-done theory. Galecki,
89
F.4th at 742
. To convict Sullivan, even under the claimed
invalid theory, the jury still would have had to find that he
“intentionally endeavored . . . to influence, obstruct, or
impede” the pending FTC investigation by “acting with an
improper purpose, . . . including . . . withholding[] [or]
concealing . . . a document or other information.” Given the
nature of the ways in which, factually, Sullivan might be
found at trial to have withheld information, we discern no
reasonable scenario in which the jury could have found that
Sullivan personally withheld information with the intent to
endeavor to influence the FTC proceeding concerning Uber
without also finding that he thereby willfully caused Uber to
violate its conceded duty to disclose. 5 We also have no
reasonable doubt that this case falls within the rule that “[i]f
the evidence that the jury necessarily credited in order to
convict the defendant under the instructions given . . . is such
that the jury must have convicted the defendant on the
legally adequate ground in addition to or instead of the
legally inadequate ground, the conviction may be affirmed.”
Galecki,
89 F.4th at 742
(citation modified). We further
conclude that it is “absolutely certain” that the jury had to
find culpability vis-à-vis willfully causing Uber to violate its

5
Sullivan makes a sufficiency-of-the-evidence challenge as to his willful
causation of nondisclosure, based solely on the fact that he disclosed the
2016 breach to Uber’s then-CEO. This argument is neither
comprehensive as to the scope of Sullivan’s alleged nondisclosure nor
supported by law. It therefore fails.
16 USA V. SULLIVAN

duty in order to find that Sullivan also personally withheld
information. Ficklin v. Hatcher,
177 F.3d 1147, 1152
(9th
Cir. 1999). Because we conclude that any error is harmless,
we need not reach the question of validity under Section
1505.
II. Sufficiency of the Evidence—Misprision
Conviction
We now turn to Sullivan’s argument that the evidence of
his alleged misprision was insufficient as a matter of law.
We review de novo. See Munoz,
412 F.3d at 1048
. We must
determine “whether, after viewing the evidence in the light
most favorable to the prosecution, any rational trier of fact
could have found the essential elements of the crime beyond
a reasonable doubt.” United States v. Laney,
881 F.3d 1100,
1106
(9th Cir. 2018) (quoting United States v. Atkinson,
990
F.2d. 501, 502
(9th Cir. 1993) (en banc)).
Misprision is the crime of “having knowledge of the
actual commission of a felony” and “conceal[ing]” or failing
to “as soon as possible make known the same to some judge
or other person in civil or military authority under the United
States.”
18 U.S.C. § 4
. To establish misprision, the
government is obliged to show that “the principal committed
and completed the felony alleged.” United States v.
Ciambrone,
750 F.2d 1416, 1417
(9th Cir. 1984). Here, that
meant proving that the hackers had “intentionally
accesse[d]” Uber’s computers “without
authorization . . . and thereby obtain[ed]” information from
those “protected computer[s],” in violation of the CFAA.
18
U.S.C. § 1030
(a)(2).
The hackers’ use of stolen credentials to access
protected, private servers was a typical CFAA violation. See
hiQ Labs, Inc. v. LinkedIn Corp.,
31 F.4th 1180, 1201
(9th
USA V. SULLIVAN 17

Cir. 2022) (holding that violation occurs “when a person
circumvents a computer’s generally applicable rules
regarding access permissions, such as username and
password requirements, to gain access to a computer”).
Nobody here argues that their access, and subsequent
downloading of data, was authorized beforehand. 6
Sullivan argues that Uber’s post hoc authorization, via
the NDA, retroactively rendered the hackers’ access
authorized—thereby erasing their felony. But this is a false
premise, inconsistent with the most plain and natural reading
of the CFAA. In the statute, “without authorization”
modifies the present-tense verb “accesses.”
18 U.S.C.
§ 1030
(a)(2). An actor’s authorization, or lack thereof, is
assessed at the moment of access. 7 Our prior decisions
support this reading. United States v. Nosal,
844 F.3d 1024,
1038
(9th Cir. 2016) (upholding a jury instruction that “[a]
person uses a computer ‘without authorization’ when the
person has not received permission” and noting that the jury

6
We need not decide whether a bug bounty program may endow
qualified researchers with prior authorization to access protected
computers.
7
Sullivan’s alternative interpretation would allow companies to “modify
the terms of authorization after initial access” and require courts to assess
“authorization” at some undetermined point after such modification. The
effects of that interpretation could endanger the existence of bug bounty
programs: If a company could apply modified terms retroactively, then
a good-faith researcher who had accessed a computer yesterday while
authorized could have that access retroactively deauthorized today.
Yesterday’s access might then constitute a violation of the CFAA.
Uncertainty regarding criminal liability could deter participation in bug
bounty programs. And allowing post hoc authorization could encourage
extortionary schemes: hackers could download sensitive data, demand a
data ransom, and then insist that the company alter its bug bounty
program terms to retroactively immunize their conduct.
18 USA V. SULLIVAN

was to determine “whether such permission was given”)
(emphases added), overruled in part on other grounds by
Lagos v. United States,
584 U.S. 577
(2018); LVRC
Holdings LLC v. Brekka,
581 F.3d 1127, 1135
(9th Cir.
2009) (“[A] person uses a computer ‘without authorization’
under [the CFAA] . . . when the employer has rescinded
permission to access the computer and the defendant uses the
computer anyway.”) (emphasis added). Because the hackers
had not been given authorization by the time of access, their
access was unauthorized. Their illegal conduct could not be
laundered through an NDA.
The government also needed to show that Sullivan had
“full knowledge” “that the principal[] had committed and
completed the felony alleged.” Lancey v. United States,
356
F.2d 407, 409
(9th Cir. 1966). Sullivan claims that, even if
the hackers were unauthorized within the meaning of the
CFAA, he reasonably believed that the NDA
recharacterizing the hackers’ conduct as part of Uber’s Bug
Bounty Program retroactively authorized the breach—
thereby cleansing the felonious access of its illegality. Given
this belief, he argues, he could not have had “full
knowledge” as required for conviction of misprision.
The evidence does not support this argument. By
November 15, 2016, Sullivan knew that an unauthorized
actor had “compromised” Uber’s accounts and potentially
“acquired” data. According to his own arguments, he
“believed that the hackers’ conduct was unauthorized at the
time it occurred,” and he “view[ed] the legality of [the
hackers’] conduct as turning on a Bug Bounty agreement.”
That is, before the NDA was signed, he knew and believed
that their conduct was illegal. If the NDA were really meant
to cleanse the felony, it would have described the incident
accurately, rather than omitting the fact that the hackers
USA V. SULLIVAN 19

downloaded Uber’s data. And the evidence suggests that
Sullivan’s beliefs did not change even after the signing: A
year after the incident, Sullivan referred to the hackers as
“unauthorized” in an email to Uber’s new CEO. Uber’s
lawyers, too, continued to characterize the hackers as
“unauthorized.”
Finally, the government had to show that Sullivan knew
that the conduct in question was a felony punishable by more
than a year in prison. “The defendant need not know the
precise term of imprisonment authorized by law, but at least
[he] must know the potential punishment exceeds one year
in prison.” United States v. Olson,
856 F.3d 1216, 1224
(9th
Cir. 2017). Sullivan had been an Assistant U.S. Attorney in
a “Computer Hacking and IP Unit.” He had helped prosecute
a CFAA violation; the plea agreement, which he signed,
noted a maximum sentence of five years. Sullivan’s unusual
“sophistication” could also be inferred “from [his]
experience” as a prosecutor and cybersecurity professional.
Id.
As detailed above, a rational juror could have found each
essential element of misprision beyond a reasonable doubt.
III. Admission of Guilty Plea
Finally, we address Sullivan’s contention that the district
court abused its discretion in permitting the introduction of
the guilty plea agreement signed by one of the hackers. We
review for abuse of discretion a district court’s evidentiary
ruling under Federal Rule of Evidence 403, which is not to
be overturned unless it is “manifestly erroneous.” United
States v. Tsarnaev,
595 U.S. 302
, 322–23 (2022) (quoting
Gen. Elec. Co. v. Joiner,
522 U.S. 136, 142
(1997)).
20 USA V. SULLIVAN

There is no manifest error here. In providing that a court
“may exclude relevant evidence if its probative value is
substantially outweighed by a danger of . . . unfair
prejudice,” Rule 403 gives the district court considerable
leeway. Fed. R. Evid. 403. The probative value of the plea
agreement is unquestionable. The agreement served as
evidence of the specific crimes to which one of the hackers
had pled guilty, including a felonious violation of the CFAA.
The agreement thus proves an element of the crime with
which Sullivan was charged. Even if we assess the plea
agreement’s probative value only “relative to the other
evidence in the case,” such as the hacker’s testimony, that
value is still significant. Old Chief v. United States,
519 U.S.
172, 185
(1997).
Any unfair prejudice to the defendant resulting from the
plea’s admission into evidence does not substantially
outweigh the plea’s probative value. Because the hacker and
Sullivan pleaded guilty to separate crimes, the fact of this
plea does not improperly impute blame for the hacker’s
conduct to Sullivan. Cf. Baker v. United States,
393 F.2d
604, 614
(9th Cir. 1968) (stating the general rule that “guilty
pleas of co-defendants cannot be considered as evidence
against those on trial,” so that the defendant’s guilt is
“determined upon the evidence against him, not on whether
a Government witness or co-defendant has pleaded guilty to
the same charge”), cert. denied
393 U.S. 836
(1968).
Contrary to Sullivan’s arguments, the plea also does not
attribute to him any particular belief. Nor are the facts within
the plea likely to cause unfair prejudice, as they were subject
to a limiting instruction by the district court that they were
not to be taken for the truth of the matter asserted. The
district court gave “adequate cautionary instruction” to
USA V. SULLIVAN 21

mitigate prejudice. United States v. Halbert,
640 F.2d 1000,
1006
(9th Cir. 1981).
We conclude that the court did not abuse its discretion in
admitting the plea and therefore decline to reach the question
of harmlessness.
Conclusion
The jury’s verdict in this case underscores the
importance of transparency even in failure situations—
especially when such failures are the subject of federal
investigation. The verdict is not tainted by any of the claimed
instructional or evidentiary errors, nor can it be overturned
for insufficiency of the evidence. We affirm the district court
in all relevant respects.
AFFIRMED.

United States v. Sullivan

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