The U.S. Justice Department told a federal judge Alphabet's Google illegally dominated online advertising technology in seeking a second antitrust win against the company.

Judge will decide whether the internet giant, already facing the prospect of a breakup over its monopolistic search engine, also runs its advertising unit as an illegal monopoly.

A federal judge will hear arguments on whether Google's advertising tech constitutes a monopoly as closing arguments begin Monday.

Canada’s antitrust watchdog is suing Google over alleged anticompetitive conduct in the tech giant’s online advertising business and wants the company to sell off two of its services and pay a penalty