WASHINGTON — A congressional investigation into the power of big tech companies began on Tuesday with bipartisan concern from lawmakers that the government’s lax oversight of the industry may be doing more harm than good.
In its first hearing about the power held by Google, Facebook, Amazon and Apple, lawmakers focused on the decline of the news industry. They said they were troubled that the online digital advertising market, which is dominated by Google and Facebook, had siphoned off too much revenue from news organizations.
“Concentration in the digital advertising market has pushed local journalism to the verge of extinction,” said Representative David Cicilline, a Democrat from Rhode Island.
The hearing was the start of the House Judiciary Committee’s inquiry into possible anticompetitive behavior by big tech companies, part of a rising wave of federal scrutiny of the industry.
The House committee plans several hearings, depositions and interviews with competitors over the next 18 months. In addition, the Justice Department and the Federal Trade Commission, the two top antitrust agencies, recently divided antitrust oversight over Apple, Amazon, Facebook and Google.
The close reviews could lead to years of troubles for the companies, through lawsuits or new laws. European regulators have already taken a tough stance against the companies, investigating how they handle user data, police speech and limit competition.
Mr. Cicilline, who is leading the Judiciary Committee’s investigation, said he would explore a variety of issues. He said the committee would look into whether the dominant social network, Facebook, had harmed consumers with its handling of data, for example. He said it also planned to look