what happened is that google is an advertising company. it's been an advertising company for a long, long time, but it's been able to tread lightly in the past due to the superior value it provided it's customers (advertisers). facebook changed that. facebook, due to a long history of questionable behaviour, is able to offer advertisers more. google finally has a rival it has to actually work at competing against and unfortunately that rival is facebook, and that sets the tone for how that competition is going to play out.