Cab drivers, limousine drivers and UberBlack operators parked their cars in the streets of Center City Philadelphia today, snarling traffic as they protested UberX and Lyft ridesharing services.

The licensed drivers who face regulations in the city feel they’re losing business to ridesharing services that remain unregulated and aren’t technically legal in Philadelphia. UberBlack drivers are legal, licensed limousine drivers, and their feud with UberX (the more traditional ridesharing experience) has been brewing for months.

In a statement, and Uber spokesperson placed the blame squarely on the Philadelphia Parking Authority, which regulates cabs in Philadelphia.

“Many taxi and limousine drivers are understandably frustrated because the Philadelphia Parking Authority’s outdated rules make it harder to earn a living when the public has shown they want more affordable options…” the spokesperson said in a prepared statement. “We believe statewide reform of the PPA that allows for regulated ridesharing will benefit both riders and drivers.”

Here are photos and tweets from the protest: