California followed through with its threat to stop Uber from testing autonomous vehicles on San Francisco's public roads.

The California Department of Motor Vehicles yesterday revoked the vehicle registrations for Uber's entire fleet of self-driving cars deployed in the State. The move has forced Uber to comply.

"We have stopped our self-driving pilot in California," an Uber spokesperson told us in an emailed statement. "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."

The drama unfolded last week when Uber officially launched its fleet of self-driving Volvo XC90 vehicles in San Francisco, available to any Uber customer hailing the company's UberX ridesharing service. California regulators were swift to criticize the move, warning Uber it was operating illegally without proper permits. The state defines autonomous cars as vehicles capable of driving "without the active physical control or monitoring of a natural person."

Uber argued it didn't need permits because its vehicles do not operate without full-time supervision from a technician in the driver's seat. California disagreed, stating that "twenty manufacturers have already obtained permits to test hundreds of cars on California roads" and Uber "shall do the same."

We asked Uber if it plans to apply for the permit, but are still awaiting a response. California's autonomous driving permit requires proof of insurance coverage of at least $5 million. Applicants must also list all vehicles and drivers involved in the program and report any "disengagement" incidents--cases that required driver intervention while the vehicle was in autonomous mode.

Uber points out that it is testing its autonomous technology in other states and has done so without the bureaucratic process California is requesting. The company hopes California will reconsider and take a more "pro technology" stance in the future.