Washington (CNN Business) The House Judiciary committee said Monday it is launching a "top-to-bottom" antitrust investigation of the tech industry, including Amazon (AMZN), Apple (AAPL), Facebook (FB) and Google (GOOG), deepening a crisis for Silicon Valley's largest players as they face mounting scrutiny in Washington over their power and influence.

The Democratic-led investigation comes as the Justice Department and the Federal Trade Commission are taking their first steps toward a potential probe of their own into Google, according to three people familiar with the matter. Regulators have negotiated to divide oversight of the tech industry between the two agencies in recent weeks, these people said. The two agencies have also reportedly split up oversight of Amazon, Apple and Facebook.

Long the darling of investors and politicians, the tech industry has come under intense pressure amid an array of privacy missteps, disinformation scandals and allegations of anti-competitive behavior. Industry critics such as Massachusetts Democratic Sen. Elizabeth Warren, a presidential candidate, have called for tough new regulations and demanded that the companies be broken up.

The industry probe will be wide-ranging. Rhode Island Democratic Rep. David Cicilline, who heads the panel's subcommittee on antitrust and is leading the investigation, said it is aimed less at specific companies than at the "tremendous concentration of market power" held by Silicon Valley's most dominant platforms.

Key areas for the investigation include the tech industry's impact on local journalism, consumer privacy and the ability for new startups to enter the marketplace, according to Cicilline. At the heart of the inquiry are concerns about what Cicilline called the companies' "tremendous market power," which in some cases he feels has led to their accumulating substantial political power.

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