IP Law Daily, TRADEMARK—D. Del.: X is still 'formerly known as Twitter' when it comes to trademark rights, court says, (Sep 8, 2026)

By Saurabh Kashyap, B.A., M.A., LL.B., LL.M.

X won an injunction protecting its Twitter-formative marks through continued use, but likely abandoned the TWEET mark and iconic Bird logo after rebranding.

A federal district court in Delaware has granted in part X Corp.’s motion for a preliminary injunction against Operation Bluebird, Inc., which sought to launch a competing social networking platform using Twitter-related branding. The court found that X was likely to succeed on its trademark infringement and dilution claims involving eight Twitter-formative marks because its continued use of “formerly known as Twitter” to promote the X app constituted bona fide trademark use. However, the court refused to enjoin Bluebird from using the TWEET mark or Twitter Bird logo, finding that Bluebird was likely to prove X had abandoned those marks after the platform’s 2023 rebranding. The injunction was conditioned on X posting a $500,000 bond (XCorp. v. Operation Bluebird, Inc., No. 1:25-cv-01510-CFC (D. Del. Sep. 3, 2026)).

Twitter. Twitter, Inc. launched its social media platform in 2006, using the Twitter name, a distinctive sky-blue color scheme, and eventually its well-known Bird logo. Millions of users accessed the service to post and comment on short messages known as “tweets.” X acquired Twitter’s assets in March 2023, including registered trademarks and pending applications covering TWITTER, TWEET, TWITTER AMPLIFY, TWITTER FLIGHT, and several versions of the Bird logo.

X rebranded the Twitter platform as X in July 2023, removing the Bird logo and references to “Twitter” and “Tweet” from the platform. At the time, X owner Elon Musk publicly stated that the company would “bid adieu” to the Twitter brand and “all the birds.” X nevertheless retained the twitter.com domain, which redirects users to x.com, and continued maintaining its Twitter-related trademark registrations.

In December 2025, Bluebird filed intent-to-use applications to register TWITTER and TWEET and announced plans for a social networking platform at twitter.new. Its website used the same sky-blue color associated with the former Twitter platform and displayed the Bird logo. Promotional messages included “We Are Bringing It Back,” “Welcome To Twitter.new,” and “#Back With Your Ex.” By December 22, more than 140,000 people had reserved usernames on the planned platform. The website included a disclaimer stating that Bluebird was not affiliated with X or Twitter, Inc.

X sued Bluebird for federal trademark infringement, counterfeiting, false designation of origin, unfair competition, trademark dilution and copyright infringement, together with Delaware-law claims, and sought a preliminary injunction barring Bluebird from using 13 registered marks it collectively called the “TWITTER Marks.” The court had previously denied preliminary relief concerning X’s copyrighted works.

Twitter-formative marks. The principal dispute concerned abandonment. Under 15 U.S.C. § 1127, a trademark is abandoned when its use has been discontinued with an intent not to resume use. Because abandonment was Bluebird’s affirmative defense, it bore the burden of proving both elements, and Third Circuit law required abandonment to be “strictly proved.”

The court found that Bluebird was unlikely to satisfy that burden for the eight Twitter-formative marks, which included TWITTER, twitter, TWITTER AMPLIFY, and TWITTER FLIGHT. The critical evidence was X’s current Apple App Store listing, which began: “Welcome to X (formerly known as Twitter).” X presented testimony that it deliberately retained that language so consumers searching for the Twitter app would understand that X was the same app and platform.

The court concluded that the reference was not merely historical. It allowed X to capitalize on the goodwill and recognition associated with Twitter while identifying the source of the rebranded service. Relying in part on Wells Fargo & Co. v. ABD Insurance & Financial Services, 758 F.3d 1069 (9th Cir. 2014), the court found that using a predecessor’s mark to connect a rebranded business to the goodwill of its former identity could constitute bona fide trademark use.

Bluebird argued that “formerly known as Twitter” communicated that X no longer offered services under the Twitter mark. The court disagreed. The phrase told consumers that the service they formerly knew as Twitter was now X and could be obtained through the X app. Its placement in explanatory text rather than as a prominent standalone trademark did not negate that source-identifying function. Accordingly, X was likely to defeat Bluebird’s abandonment defense and succeed on its infringement and dilution claims involving the Twitter-formative marks.

TWEET mark and Bird logo. The result differed for TWEET and the Bird logo. Neither appeared in X’s App Store listing or on the x.com home page. X relied on vendor-onboarding materials, old webpages, legacy social media accounts, third-party brand guidelines, and older versions of its mobile app as evidence of continued use.

The court found those materials insufficient. Many webpages predated the rebranding or lacked evidence of current use, while old Twitter-branded social media accounts were inactive. The @twitter account on X had been deactivated and directed users to follow @x. Such material constituted remnants of earlier trademark use rather than present bona fide use in commerce.

X’s vendor-onboarding materials also did not establish trademark use because they solicited services from vendors rather than advertised or sold X’s services. Its brand guidelines controlled how third parties could display Twitter marks but did not establish the control over the nature and quality of third-party goods or services necessary for their use to benefit X under 15 U.S.C. § 1055.

The court also found compelling evidence that X intended not to resume using TWEET and the Bird logo. Musk’s 2023 statements about abandoning the Twitter brand and birds, combined with X’s actual rebranding, outweighed litigation-era assertions suggesting otherwise. Bluebird therefore was likely to prove abandonment of those marks, meaning X was not likely to succeed on infringement or dilution claims based on them.

Irreparable harm and injunction. As to the Twitter-formative marks, X was entitled under 15 U.S.C. § 1116(a) to a rebuttable presumption of irreparable harm based on its likelihood of success, and Bluebird presented no evidence overcoming that presumption. The record also included a Bluebird co-founder’s public statement that hundreds of millions of people searched for “twitter” monthly and were finding Bluebird’s site. Bluebird did not meaningfully address the balance of equities or public interest and therefore forfeited challenges based on those factors.

Finally, the court rejected Bluebird’s request for a bond of at least $50 million, which rested on projections that its Twitter-branded platform could attract 10 million users and generate $55 million in first-year revenue. The court characterized the user projection as speculative and found lost revenue an improper measure without evidence of costs or lost profits. It instead accepted X’s proposed $500,000 bond.

The court therefore enjoined Bluebird from using the Twitter-formative marks pending trial, conditioned on X posting the bond, but denied preliminary relief covering the TWEET mark and Bird logo.

The Case is No. 1:25-cv-01510-CFC.

Judge: Connolly, C.

Attorneys: Andrew C. Mayo (Ashby & Geddes) for XCorp. Brian E. Farnan (Farnan LLP) for Operation Bluebird, Inc.

Companies: XCorp.; Operation Bluebird, Inc.

Cases: Trademark DelawareNews TechnologyInternet