On August 20, 2025, the U.S. Court of Appeals for the Second Circuit issued a significant decision concerning the scope of immunity under Section 230 of the Communications Decency Act (CDA). In United States v. EZ Lynk et al., the Second Circuit held that the defendants—alleged to have promoted defeat devices on an online software platform—could not claim Section 230 immunity at the motion to dismiss stage because the government adequately alleged that the defendants “directly and materially contributed to” unlawful third-party delete software.
District Court Decision
The United States, on behalf of the U.S. Environmental Protection Agency, alleged that EZ Lynk violated the Clean Air Act (CAA) by selling the “EZ Lynk System.” That system allegedly has three components: 1) the physical device that plugs into the vehicle, 2) the cloud service (EZ Lynk Cloud) that allows storing and sharing of software, called “tunes,” and 3) an app that connects the physical device to the cloud. Tunes adjust vehicle operations in the engine’s electronic control unit and, in some cases, can defeat the emission controls. The tunes available in the EZ Lynk Cloud are created by third party software developers, not the defendants, although the government alleged that EZ Lynk worked with at least two of these developers.
The government alleged that the EZ Lynk System was a defeat device. Although the EZ Lynk System may be sold without any tunes and the physical device is also sold on its own, many retailers sell the EZ Lynk System bundled together with tunes. And many of those tunes are capable of defeating or bypassing a vehicle’s emission control system. EZ Lynk filed a motion to dismiss, arguing the EZ Lynk System is not a defeat device and claiming immunity under CDA Section 230.
Under CDA Section 230, “[n]o provider or user of an interactive computer service shall be treated as the publisher or speaker of any information provided by another information content provider.” 47 U.S.C. § 230(c)(1). But the provision does not offer complete immunity, and a publisher may be held liable if it “directly and ‘materially’ contributed to what made the content itself ‘unlawful.’” Force v. Facebook, Inc., 934 F.3d 53, 68 (2d Cir. 2019).
The U.S. District Court for the Southern District of New York held that the EZ Lynk System is a defeat device but that EZ Lynk was immune from CAA liability under the CDA. The court found that EZ Lynk was merely the provider of the “platform” or “interactive computer service” where users found third-party software to interfere with their vehicles’ emissions systems. The government’s allegations thus fell “far short of alleging direct and material contributions to illegal activity” that would defeat immunity.
Second Circuit Opinion
The United States appealed, arguing that EZ Lynk is “a manufacturer and seller of a system that installs unlawful emissions-control defeating software” and therefore is not immune as a publisher under CDA Section 230. EZ Lynk disputed the government’s characterization, arguing that it only “manufactures a wireless pass-through interface and smart phone application” and “neither creates nor sells any content, unlawful or otherwise, that users” allegedly transmit through the EZ Lynk System.
The Second Circuit vacated the district court’s opinion because the United States’ allegations “support[ed] an inference that [EZ Lynk] ‘directly and materially contributed to’ the creation of delete tunes.” The court found that “[u]nder that inference, Appellees ‘did not merely act as . . . neutral intermediar[ies]’ between the delete tunes creators and vehicle owners ‘but instead specifically encourage[d] development of what [was] offensive about the content.’”
The court relied on a number of EZ Lynk’s actions, as alleged in the government’s complaint:
- EZ Lynk worked with/previewed the EZ Lynk System for at least two delete tune creators during development and before launching the EZ Lynk System. Those creators later disseminated delete tunes using the EZ Lynk System.
- There were numerous social media websites, including the “EZ Lynk Forum,” where third parties discussed using the EZ Lynk System to defeat emission controls. The Forum was run by EZ Lynk and one of the delete tune creators EZ Lynk worked with during development, and it provided contact information for EZ Lynk technical support.
- EZ Lynk representatives interacted with posts and videos about deleting emission controls and installing delete tunes, including tunes from one of the delete tune creators EZ Lynk worked with during development.
The Second Circuit remanded the case to the district court but clarified that its holding was limited to the facts alleged in the complaint and that discovery may uncover facts that refute the government’s allegations or undermine the inferences about EZ Lynk’s involvement in creating the unlawful content.
EZ Lynk could seek review by the full Second Circuit or petition the U.S. Supreme Court to take up the case. EZ Lynk could also litigate the case on remand, seeking to develop facts to rebut the government’s allegations.
