Hundreds of Philly cabbies and Uber Black drivers joined forces to block the streets around City Hall in protest of UberX and Lyft on Wednesday, causing midday gridlock in Center City.

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​"Stop UberX" one driver had written on their back windshield. "Uber and Lyft cannibalize legal drivers," was a sign on another car.

The protest was scheduled to carry on through 3 p.m. As of Wednesday around 2 p.m., protesters were driving to 30th Street Station.

Organizers said the protest was specifically targeted against UberX, the version of the UberX app where drivers use their own cars which has been illegally operating in Philadelphia for a year, and Lyft, a similar service to Uber.