The Justice Department is demanding Apple, Google, Amazon, and Walmart hand over names, addresses, and purchase histories of more than 100,000 people who downloaded a car-tuning app, and Apple and Google are preparing to fight back.
The subpoenas target EZ Lynk, a Cayman Islands-based company whose Auto Agent app pairs with an OBD hardware dongle to let users modify vehicle software. The DOJ sued EZ Lynk in 2021 for allegedly selling "defeat devices" that bypass factory emissions controls on diesel vehicles, violating the Clean Air Act.
What makes this case different from typical environmental enforcement is the scope of the data grab. According to a joint court filing, the DOJ subpoenaed Apple and Google in March and April for download and account data on every single person who installed the Auto Agent app.
Amazon and Walmart received similar requests for buyer information on the physical hardware. The total could exceed 100,000 individuals, roughly 10 times larger than a similar 2019 demand for data on users of a gun-scope app.
EZ Lynk's lawyers are calling the requests "overreach." In the joint letter, they wrote that the subpoenas "go well beyond the needs of this case and create serious privacy concerns." Apple and Google are reportedly preparing to challenge the demands, according to the filing.
The government argues it needs the data to find witnesses who can testify about how EZ Lynk's tools were actually used. The DOJ has already submitted Facebook posts and forum messages showing some users disabling emissions controls. In the letter, the government said its request was "fair and appropriate" and that it had "consistently sought customer information."
Privacy advocates see a broader threat. Tom McBrien of the Electronic Privacy Information Center told Forbes it's "worrying that the government could obtain personally identifiable information for every customer through discovery, which is outside of the privacy protections provided by the Fourth Amendment."
The DOJ argued in the letter that EZ Lynk users surrendered their privacy rights when they agreed to the company's terms of service. Aaron Mackey of the Electronic Frontier Foundation called that argument "particularly problematic," noting most people never read terms and that such broad data collection "raises questions about why they want this data and what they're going to use it for beyond the prosecution of this case."
The case has a tangled legal history. EZ Lynk previously tried to invoke Section 230 immunity, the same law that shields social media platforms from liability for user content, arguing it shouldn't be held responsible for how customers used its tools. A judge rejected that defense in August 2025.
Justin Montalbano, president of the Car Hacking Village at Def Con, said the government's approach misses the mark.
"People want to modify their cars and always will, regardless of laws," he told Forbes.
He suggested mandatory annual vehicle inspections for defeat devices as a more targeted alternative. The outcome of any challenge to the subpoenas could set a precedent for how far the government can reach into app store data for enforcement actions. Apple, Google, Amazon, and Walmart have not publicly commented. The DOJ declined to elaborate beyond its court filings.
