The U.S. Justice Department announced last week that it was opening investigations into whether large technology companies are violating antimonopoly laws and misusing their position in the market. It specified in an official statement that it would examine “whether and how market-leading online platforms have achieved market power and are engaging in practices that have reduced competition, stifled innovation, or otherwise harmed consumers.”

The inquiry involves Facebook, Google, Amazon and Apple, according to Reuters News Agency. None of the technology giants was willing to comment on the Justice Department’s announcement, and all suffered an immediate decline in stock values.

It was also made public, concurrently with the announcement on antitrust proceedings, that the Federal Trade Commission, which is also responsible for consumer protection, fined Facebook a record $5 billion for failing to protect users’ personal data. Facebook admitted to unauthorized handling of its clients’ data and agreed to pay the fine.

And a third point: before the legislature recessed, Republican Senator Josh Hawley proposed a bill to prohibit social networking sites from violating principles of neutrality of opinion and censoring users’ political postings. A company’s employees and algorithms would also be prohibited from violating opinion neutrality, and the FTC would monitor compliance and enforce it with sanctions. The same commission that just this month assessed Facebook with that huge fine.

Hawley’s bill would apply to online platforms with more than 30 million users in the U.S. or more than 300 million worldwide, or those that have worldwide revenues exceeding $500 million.

The Trump administration, with support from many Democrats no less, is striking back at big tech firms and trying to limit their exponentially increasing political influence.

When Facebook and Twitter intensified the practice of blocking conservative posts and deleting right-wing activists’ accounts a couple of months ago, the American president tweeted, “Twitter should let the banned Conservative Voices back onto their platform, without restriction. It’s called Freedom of Speech, remember. You are making a Giant Mistake!”

It wasn’t very savvy of Facebook to prohibit Trump from running an ad on his wife Melania’s birthday this spring. All because the post contained the address “Attention Ladies” – and that, according to Facebook, is impermissible and in conflict with the social site’s rules. In posts of an advertising nature, it’s prohibited to indicate attributes of the target audience, including gender.

But President Trump takes some things personally, and he’s good at keeping his word. Huge tech companies like Facebook and Google are now threatened not only with stiff fines, but also with having their firms broken up.