Update, 4 p.m. Friday: Lyft has issued a response to the injunction threat from the San Francisco and L.A. DAs:
Ridesharing has been enthusiastically embraced by California residents and we have worked closely with the California Public Utilities Commission over the past two years to secure a future for this innovative option throughout the state. We are confident that we can work with the District Attorneys' offices to address the items outlined in their letter and look forward to discussing with them soon to do so.
Original post (Thursday): San Francisco District Attorney George Gascón and his counterpart in Los Angeles are threatening action against ride-service companies Uber, Lyft and Sidecar over alleged violations of state law.
In a letter to San Francisco-based Sidecar (embedded below), Gascón said an investigation conducted with L.A. County District Attorney Jackie Lacey has found the company has made misleading statements about its background checks on drivers and has illegally quoted individual fares for passengers.
The letter promised legal action against the company unless it meets with prosecutors by Oct. 8 to discuss how it will remedy the alleged violations.
The San Francisco District Attorney's office confirmed that letters had been hand-delivered to Uber, Lyft and Sidecar on Thursday, but declined to provide copies. The San Francisco Chronicle reported that the DAs made similar allegations against all three companies.