NOT FOR PUBLICATION FILED

UNITED STATES COURT OF APPEALS DEC 19 2025

MOLLY C. DWYER, CLERK

U.S. COURT OF APPEALS

FOR THE NINTH CIRCUIT

MEDIA MATTERS FOR AMERICA; No. 25-2463 ANGELO CARUSONE; ERIC D.C. No. HANANOKI, 3:25-cv-02397-VC Plaintiffs - Appellees,

MEMORANDUM*

v.

X CORP.; TWITTER INTERNATIONAL

UNLIMITED COMPANY; TWITTER

ASIA PACIFIC PTE, LTD.,

Defendants - Appellants.

Appeal from the United States District Court for the Northern District of California Vince Chhabria, District Judge, Presiding

Argued and Submitted November 17, 2025 San Francisco, California

Before: BOGGS, BRESS, and MENDOZA, Circuit Judges.**

Media Matters published an article claiming that X Corp.’s (“X”) content

moderation policies permitted the placement of “pro-Nazi” content next to

* This disposition is not appropriate for publication and is not precedent except as provided by Ninth Circuit Rule 36-3. ** The Honorable Danny J. Boggs, United States Circuit Judge for the Court of Appeals, Sixth Circuit, sitting by designation. advertisements for major brands. In response, X and its foreign subsidiaries sued

Media Matters in three jurisdictions, including Ireland. After litigating for over a

year in Ireland, Media Matters brought suit in the Northern District of California,

invoking a forum selection clause in X’s terms of service. The district court entered

an anti-suit injunction that enjoined X from pursuing the Ireland litigation.

We “review[ ] the district court’s decision to grant or deny a preliminary

injunction for abuse of discretion,” but “[t]he district court’s interpretation of the

underlying legal principles . . . is subject to de novo review.” Cal. Chamber of Com.

v. Council for Educ. & Rsch. on Toxics, 29 F.4th 468, 475 (9th Cir. 2022) (quotation

marks and citation omitted). We have jurisdiction under 28 U.S.C. § 1292(a)(1), and

we vacate the injunction.

1. As an initial matter, the district court had subject matter jurisdiction based

on diversity of citizenship. See 28 U.S.C. § 1332(a). X challenges only the amount

in controversy, but its challenge fails. A court can only dismiss a case on amount-

in-controversy grounds if it “‘appear[s] to a legal certainty’” that the controversy

will not exceed $75,000 in value. Geographic Expeditions, Inc. v. Est. of Lhotka ex

rel. Lhotka, 599 F.3d 1102, 1106 (9th Cir. 2010) (quoting Crum v. Circus Circus

Enters., 231 F.3d 1129, 1131 (9th Cir. 2000)).

Here, the value of an injunction to Media Matters likely exceeds $75,000. See

Corral v. Select Portfolio Serv., Inc., 878 F.3d 770, 775 (9th Cir. 2017) (explaining

2 25-2463 that “[i]n actions seeking declaratory or injunctive relief, it is well established that

the amount in controversy is measured by the value of the object of the litigation”)

(quoting Cohn v. Petsmart, Inc., 281 F.3d 837, 840 (9th Cir. 2002)). X, if successful

in the Ireland litigation, would likely be entitled to more than $75,000 in damages.

A successful anti-suit injunction would terminate the foreign action and also prevent

Media Matters from enduring some duplicate litigation (likely producing savings

even if X re-files in the United States). X argues that since its terms of service limit

liability to $100, Media Matters’ recovery is limited to an amount less than $75,000.

But “‘the existence of a valid defense to [a] claim’ does not eliminate federal

jurisdiction.” Geographic Expeditions, 599 F.3d at 1108 (quoting St. Paul Mercury

Indem. Co. v. Red Cab Co., 303 U.S. 283, 289–90 (1938)).1

2. The parties dispute whether Media Matters has the right to enforce X’s

terms of service against X’s foreign affiliates. But we conclude that even if Media

Matters had such a right, it waived the right to exercise the forum selection clause in

X’s terms by actively litigating the Ireland case for over a year without raising the

forum selection clause in either Ireland or the Northern District of California.

1 Media Matters also meets the amount in controversy based on its claimed damages in the form of attorneys’ fees for X’s alleged violation of the forum selection clause. See, e.g., Microsoft Corp. v. Motorola, Inc., 795 F.3d 1024, 1049 (9th Cir. 2015); Copenbarger v. Morris Cerullo World Evangelism, Inc., 239 Cal. Rptr. 3d 838, 844– 46 (Cal. Ct. App. 2018).

3 25-2463 Waiver can be based on a party’s litigation conduct. See, e.g., Hill v. Xerox

Bus. Servs., LLC, 59 F.4th 457, 471 (9th Cir. 2023) (explaining that parties waive

their right to enforce an arbitration clause (a type of forum selection clause) when

they delay enforcement “by actively litigating [their] case,” such as by “answer[ing]

complaints, mov[ing] to dismiss the action, and [failing to] claim a right to

[enforcement] in any of the pleadings”) (quoting Martin v. Yasuda, 829 F.3d 1118,

1125 (9th Cir. 2016)). In this case, Media Matters had knowledge of X’s terms of

service from the beginning of the Ireland litigation (and cited them in its briefs for

other jurisdictional defenses before the Irish court), so it had all the information it

needed to defend its rights. Yet instead of invoking the forum selection clause,

Media Matters litigated in Ireland for over a year before it raised the issue for the

first time in this action. Whether Media Matters failed to raise the forum selection

clause earlier due to gamesmanship or the potential negligence of its prior counsel

is not dispositive, as the parties agreed at oral argument. See Hansen v. W.

Greyhound Ret. Plan, 859 F.2d 779, 783 (9th Cir. 1988) (“[L]ack of actual

knowledge is not dispositive—waiver may be based on constructive knowledge.”).

X has also demonstrated prejudice resulting from Media Matters’ litigation

conduct. See 13 Williston on Contracts § 39:15 (4th ed.) (“[T]he probability that a

court will find a waiver or other excuse for nonperformance increases in proportion

to the extent and unfairness of the forfeiture involved.”). In the Ireland litigation,

4 25-2463 the parties submitted hundreds of pages of affidavits and other evidence that would

have otherwise been unnecessary in the context of the underlying dispute. Media

Matters’ excessive delay in raising the forum selection clause, coupled with the

litigation already conducted in Ireland, prejudiced X. This conclusion is, if anything,

even stronger in the context of an anti-suit injunction, which turns on principles of

equity. See E. & J. Gallo Winery v. Andina Licores S.A., 446 F.3d 984, 993 (9th Cir.

2006).

Media Matters argues that it has consistently contested jurisdiction in Ireland.

But that is not determinative. The right that Media Matters seeks to enforce through

the forum-selection clause is the contractual right to litigate the case before a

different tribunal in San Francisco—not the right to terminate the Irish litigation on

jurisdictional grounds. Media Matters also urges us to look to our arbitration case

law to find that a party needs to “actively litigate[ ] the merits of a case” for there to

be waiver. Armstrong v. Michaels Stores, Inc., 59 F.4th 1011, 1015 (9th Cir. 2023)

(emphasis added); see also Newirth ex rel. Newirth v. Aegis Senior Cmtys., LLC, 931

F.3d 935 (9th Cir. 2019). But these cases are inapposite, as the parties there

affirmatively raised their right to arbitrate early on. See Armstrong, 59 F.4th at 1015;

Newirth, 931 F.4th at 942. In contrast, Media Matters never invoked the forum

selection clause until over a year into the Ireland litigation. And it actively litigated

the case on other grounds in Ireland. See Hill, 59 F.4th at 471.

5 25-2463 Media Matters argues that it did not waive reliance on the forum selection

clause because it had no obligation to raise that issue in Ireland. But even so, Media

Matters failed to raise the forum-selection clause in either Ireland or California for

over a year while it actively litigated the Irish case using other theories. That is

enough to find waiver. Indeed, Media Matters’ position would seemingly permit it

to litigate in a foreign forum right up to the expiration of the statute of limitations,

then sue to enjoin the foreign litigation in the United States. We are aware of no

precedent supporting that approach.

For these reasons, we conclude that the district court erred in enjoining the

Ireland litigation because Media Matters waived its right to invoke the forum

selection clause in a California court.

3. The district court’s injunction also prevents the “X entities . . . from

prosecuting or initiating litigation outside of the United States against Media Matters

that arises from [the] same conduct alleged in the Ireland and Singapore complaints.”

This portion of the injunction appears contingent on the anti-suit injunction issued

against the Ireland litigation, which we have vacated. For this reason, we vacate the

district court’s injunction in full. On remand, the district court may consider whether

an injunction against other possible foreign litigation is necessary or appropriate.2

2 In light of our resolution of this appeal based on waiver, we have no occasion to reach X’s other assignments of error. X’s motion to stay proceedings in the district court, Dkt. 31, is denied as moot. The parties shall bear their own costs on appeal.

6 25-2463

VACATED AND REMANDED.

7 25-2463