Brief primer. Google dominates search and has a big grip on the browser and mobile OS market, but makes the vast majority of its cash from ads. The path to ad dominance was littered with blatantly illegal actions that are now coming home to roost. And the wildest of them all may be its alliance with Facebook. Facebook Inc. and Alphabet Inc.’s Google agreed to “cooperate and assist one another” if they ever faced an investigation into their pact to work together in online advertising, according to an unredacted version of a lawsuit filed by 10 states against Google last week.