Taxi medallion holders seeking court protection against competition from ride-sharing firms have lost once again.

Last month, a three-judge panel of the 3rd U.S. Circuit Court of Appeals affirmed the dismissal of a case brought by the Philadelphia Taxi Association and 80 taxi companies alleging violations of antitrust law by ride-sharing giant Uber.

Specifically, the once-dominant taxi firms wanted the court to rule that Uber's initial operations in Philadelphia were "illegal, predatory, and led to a sharp drop in the value of taxicab medallions as well as a loss of profits." Traditional taxis are, they say, losing money due to the undesired competition—and they wanted courts to bail them out.

But, as Judge Marjorie Rendell wrote in the court's opinion in Philadelphia Taxi Association, Inc. v. Uber Technologies, Inc., the purpose of antitrust laws is "to protect competition, not competitors."