On Wednesday night, the California DMV (Department of Motor Vehicles) issued a statement saying it would revoke the registrations of 16 cars owned by Uber, which the company had been using to test its self-driving system. The DMV said that “the registrations were improperly issued for these vehicles because they were not properly marked as test vehicles.”

The move from the California DMV comes after a contentious public battle last week, when Uber suddenly announced the launch of its pilot program in San Francisco (the same program had been running in Pittsburgh for a few months already). But Bloomberg noted that the ride-hailing company still hadn’t registered with the state’s DMV, which requires that companies looking to test self-driving cars apply for a special permit to do so on public roads.

Uber countered that its system wasn’t very advanced yet and was indistinguishable from a mere Advanced Driver Assistance System (ADAS), which does not require special permits. Uber cited Tesla’s autopilot software, which drivers currently use without adhering to the DMV's autonomous vehicle rules. Tesla, however, has registered with the state’s motor department to test autonomous vehicles.

Late Friday last week, California’s Attorney General sent a letter to Uber demanding that it cease its self-driving car pilot program until Uber files for a permit to test its cars on state roads. Uber responded with a press call in which its vice president of advanced technologies, Anthony Levandowski, said that since the company did not believe its cars qualified as autonomous vehicles, it would not comply with the attorney general’s order or seek a permit.

Tonight, Uber e-mailed a statement saying that rather than apply for the permit required by the DMV, Uber would cancel its pilot program in the state. “We’re now looking at where we can redeploy these cars but remain 100 percent committed to California and will be redoubling our efforts to develop workable statewide rules,” an Uber spokesperson said.

In an e-mail to the press, a DMV spokesperson said, “Uber is welcome to test its autonomous technology in California like everybody else, through the issuance of a testing permit that can take less than 72 hours to issue after a completed application is submitted. The department stands ready to assist Uber in obtaining a permit as expeditiously as possible.”

The DMV attached the letter (PDF) that it sent to Davis White, Uber’s director of public affairs for California, in which the department offered Uber a link to the application materials necessary to get a permit to test self-driving cars in the state.