The U.S. Department of Justice is considering whether to demand a breakup of Google after the search giant was ruled to be an illegal monopoly. It could be the biggest antitrust action in decades.The Justice Department submitted a filing on Tuesday that outlined a range of options from conduct restrictions to a breakup of Google’s business.

Google-parent Alphabet stock dipped in early-hours trading on Wednesday on news that the U.S. Department of Justice was mulling a breakup of the search giant after it was ruled to be an illegal monopoly.

A major part of the plan involves forcing Google to share crucial data, including its search indexes and ranking algorithms, which power its search engine and AI capabilities