The last few days have seen a flurry of activity and put four of the biggest tech companies in the world in the sights of regulators.

Stocks in all four of the major tech companies fell sharply on Monday with the news.

It’s bad news for Facebook, which is already looking at a potential $5 billion fine from the FTC concerning privacy issues and the way data is handled.  Prior to the company’s recent earnings report, Facebook reps said they had set aside $3 billion for potential fines.

Facebook is also looking at substantial fines from UK regulators in the wake of the Cambridge Analytica scandal that could top a billion dollars.

Google was hit with a $57 million fine by French data protection authority officials for processing personal data for advertising purposes with valid authorization.  That may be just the beginning of fines for tech companies.  There are multiple investigations underway for violations of the GDPR (General Data Protection Regulations) enacted in the EU last year.  So far, 59,000 data breaches have been reported and 91 fines handed out.  The Wall Street Journal reported that “large GDPR fines are imminent.”

Amazon and Google have been under the microscope from consumer advocates that claim the companies favor their own products over competitors.  Google has now been fined more than $9 billion in three separate actions by the EU.

Apple, Amazon, Facebook, and Google all face more complaints and probes in Europe.

Apple’s been hit by regulators before as well.  A $450 million fine from the FTC was levied against Apple for alleged price fixing for eBooks.  There’s also another antitrust case against Apple that revolves around allegedly monopolistic practices in the App store and pricing.  That case is before the U.S. Supreme Court while a similar complaint against Apple has been filed in the EU by Spotify.

If that wasn’t enough. The U.S. House subcommittee on anti-trust, headed by Rep. David Cicilline (D-Rhode Island) is undergoing a “sweeping review” of Facebook and Google.  The lawmaker told the Washington Post they may also look at Amazon and Apple.

“A small number of dominant, unregulated platforms have extraordinary power over commerce, communication, and information online…Based on investigative reporting and oversight by international policymakers and enforcers, there are concerns that these platforms have the incentive and ability to harm the competitive process.” – Judiciary Committee News Release featuring Democratic and Republican members