Ahead of the first congressional anti-trust hearing in decades on Wednesday, a corporate watchdog group unveiled a pair of digital tracking tools documenting how Amazon, Google, Facebook, and Apple have used monopoly power acquired through mergers and acquisitions to bilk consumers, abuse workers, and “threaten our democracy itself.”

The American Economic Liberties Project’s (AELP) Big Tech Merger Tracker shows that the four tech behemoths have completed a combined 573 acquisitions since 1988, the year Apple bought up four of its potential competitors.

“Amazon, Apple, Facebook and Google use mergers and acquisitions to gain market power, acquire data, and snuff out any threats from would-be competitors,” said AELP. Out of the four companies, Google leads the way with 255 publicly-disclosed acquisitions, followed by Apple with 121 and Amazon with 111.

The group’s Big Tech Abuse Tracker lists dozens of harmful recent actions by the four tech giants that, according to AELP, stem directly from their consolidation of power in the technology, social media, and e-commerce markets.

“Their monopoly power immunizes them from competitive or consumer pressure,” the group says, “so policy change is the only path to achieving meaningful, sustainable reform.”

Among the abuses AELP cites are Amazon’s retaliation against employees in March for blowing the whistle on the company’s handling of the Covid-19 pandemic; Apple’s failure to pay workers for time spent participating in mandatory bag and device checks; Facebook’s decision this year to allow misinformation in political ads posted on its platform; and Google’s 2019 firing of four workers who were attempting to form a union.

“From promoting racist propaganda to collecting user data without consent to spreading misinformation during a global pandemic, Apple, Amazon, Facebook and Google have been caught directly threatening civil rights, public health, and the durability of our democracy,” AELP said.

AELP’s new tools come as Amazon CEO Jeff Bezos, Google CEO Sundar Pichai, Facebook CEO Mark Zuckerberg, and Apple CEO Tim Cook are set to testify at 12:00pm ET Wednesday before the House Subcommittee on Antitrust, Commercial, and Administrative Law. The hearing is part of the subcommittee’s 13-month investigation into possible violations of anti-trust law by major tech corporations.

Sarah Miller, executive director of AELP, said in a statement Wednesday that “policymakers and enforcers have allowed these big tech barons to bully workers, consumers, and businesses for far too long.”

“The outcome of the subcommittee’s investigation into their monopoly power is central not only to whether markets will become more fair, but whether Congress will reassert its power over a handful of men whose corporations threaten our democracy itself.”