Google and Facebook took particularly sharp jabs from Democrats and Republicans on Wednesday for alleged abuse of their market power, in a much-anticipated congressional hearing that put four of America's most prominent technology CEOs in the hot seat.

The chairman of the U.S. House of Representatives antitrust panel holding the hearing said afterwards that the four CEOs had acknowledged concerning behavior.

"What we heard from witnesses at the hearing confirmed the evidence that we have collected over the last year," said Representative David Cicilline, a Democrat.