The House Judiciary Committee is launching an investigation into giant tech companies like Facebook and Google to determine whether they are abusing their market dominance and violating antitrust law.

“The open internet has delivered enormous benefits to Americans, including a surge of economic opportunity, massive investment, and new pathways for education online,” Judiciary Chairman Jerrold Nadler (D-NY) said in a statement. “But there is growing evidence that a handful of gatekeepers have come to capture control over key arteries of online commerce, content, and communications.”

The investigation comes amid growing tensions between regulators and Silicon Valley. Over the past few days, reports surfaced that the Federal Trade Commission and the Justice Department were making arrangements as to which agency would be in charge of investigating individual tech companies. The FTC will be in charge of Facebook and Amazon, and the Justice Department will have the authority to go after Google and Apple.

In March, Sen. Elizabeth Warren (D-MA) announced that, if elected president in 2020, she would work to undo consummated tech mergers (Facebook’s Instagram acquisition, for example) and introduce legislation enforcing new antitrust standards for tech companies.

Rep. David Cicilline (D-RI) will lead the investigation as chair of the committee’s antitrust sub-panel, and said today that he would be looking into Silicon Valley as a whole rather than taking aim at specific companies. Cicilline also said that he would like to hear from company executives and could issue subpoenas if they do not agree to testify in the future.

Investigators will document competition problems, analyze whether large companies are abusing their power, and look into possible new legislation that would address these concerns, according to a press release.

“Big Tech plays a huge role in our economy and our world,” Rep. Doug Collins (R-GA) said. “As tech has expanded its market share, more and more questions have arisen about whether the market remains competitive. Our bipartisan look at competition in the digital markets gives us the chance to answer these questions and, if necessary, to take action.”

Apple, Facebook, and Amazon did not immediately respond to request for comment. Google declined to comment.