Democratic lawmakers are calling for the U.S. to rein in the power of technology titans Amazon, Apple, Facebook and Google, as well as overhauling U.S. antitrust law, in a sweeping report on the dominance of Big Tech in American lives and markets.

The 450-page report, released Tuesday by the House Antitrust Subcommittee, details a range of anticompetitive practices, charging the four companies with acting as gatekeepers, stifling competition, charging “exorbitant” fees and eroding democracy.

“Put simply, companies that once were scrappy, underdog startups that challenged the status quo have become the kinds of monopolies we last saw in the era of oil barons and railroad tycoons,” the report said.