A U.S. judge's ruling that Google has illegal monopolies in ad technology sets up the possibility of U.S. prosecutors seeking a breakup. Here's what the case involves and what Google owner Alphabet faces from here.

A federal judge ruled that Google illegally cornered the online advertising market by linking its tools together to block out competition, a major win in a broader antitrust crackdown on Big Tech. The ruling found Google liable for willfully using a series of "anticompetitive acts" to dominate

Alphabet's Google illegally dominated two markets for online advertising technology, a federal judge said on Thursday, dealing another blow to the tech titan in an antitrust case brought by the U.S. U.