To find Silicon Valley’s toughest cop and critic, hop a flight and head roughly 5,500 miles across the Atlantic Ocean to Brussels.

That’s where Margrethe Vestager serves as the European Union’s chief competition regulator — and it’s a perch from which she’s swiped at Apple, Amazon, Facebook and Google even at a time when the U.S. government seems a little lost on how exactly to regulate the tech industry.

Since becoming an EU commissioner in 2014, Vestager has emerged as the unrivaled antagonist to the tech industry’s take-no-prisoners style. She’s armed with the power of the region’s expansive commerce and consumer protection laws — rules that govern everything from mergers to online privacy more aggressively than similar regulations in the U.S.

To that end, Vestager recently has set her sights on Apple and Amazon, forging ahead with two major probes that allege the two tech giants dodged billions of dollars’ worth of European taxes. Both companies are now fighting her demands for payback.

Vestager has also penalized Facebook: In May, she charged that the social giant broke its promise to her when it began harnessing data from users on WhatsApp — something that Facebook initially said it would not do.

And perhaps no tech giant has quite faced the sting of Vestager’s scrutiny like Google.

The EU competition regulator revived a long-dormant antitrust probe of the search giant once she took office, and earlier this year, she slapped Google with a record-breaking $2.7 billion fine for prioritizing its shopping search service over rivals’ offerings. Vestager also has threatened additional penalties over Google’s Android operating system. The totality of her efforts could force Google’s parent, Alphabet, to rethink broad portions of its search and mobile business worldwide.

Such a willingness to go toe-to-toe with the largest U.S. corporations seems in stark contrast to Vestager’s peers in the States, who often bristle at the tech industry’s fast-growing footprint but rarely, if ever, translate their criticisms into regulation.

Her office’s closest analog in Washington, D.C., the Federal Trade Commission, didn’t publicly rebuke Facebook over WhatsApp, for example, despite pleas from privacy critics. Nor did the FTC proceed with its antitrust probe of Google, choosing instead in 2013 to settle its investigation with the tech giant.

Meanwhile, Amazon has continued its breakneck expansion, snapping up Whole Foods this year with little objection from the U.S. government’s competition cops. And Apple and the rest of the tech industry stand to benefit greatly as a result of reforms to the U.S. tax code that are now being debated on Capitol Hill.

To some, Vestager’s efforts have smacked of protectionism. Repeatedly, though, the longtime Danish bureaucrat has insisted she’s just the steward of EU law. As Vestager herself put it during an international conference in November: “It is important for any company to respect the rules of the game.”

This article originally appeared on Recode.net.