If a judge orders Google to sell Chrome, it could dramatically upend the multibillion-dollar online search business.

Back in August a U.S. federal court found Google guilty of violating anti-trust laws, and the fallout could be the biggest antitrust action since the breakup of AT&T/Bell way back in the 1980s. But exactly what the enforcement action will look like is still very much in the air.

Alphabet Inc.’s Chrome browser could go for as much as $20 billion if a judge agrees to a Justice Department proposal to sell the business, in what would be a historic crackdown on one of the world’s biggest tech companies.