Lead litigant Checker Cab Philadelphia and the other cab operators accused Uber of racketeering.

"Not since the days of bootlegging has there been a criminal enterprise so brazen and open as to attract hundreds of millions of dollars in investment from investment bankers and to operate in blatant violation of federal and state law as Uber," reads the complaint. The case was filed in the Eastern District of Pennsylvania.

Checker Cab Philadelphia and the plaintiffs group sued Uber; its chief executive officer, Travis Kalanick; Delaware-registered entities tied to Uber; and Google Ventures, which has invested $258 million in Uber.

The suit also names 18 individuals, including Uber drivers it says are operating illegally in the city.

Pennsylvania's Public Utility Commission recently allowed UberX to operate in the state, but not in Philadelphia, where taxis are regulated by the Philadelphia Parking Authority.