runs one of the biggest online ad networks in the world. There’s a good chance that almost every website you visit has ad banners that Google operates. Being really popular means scammers will target will constantly target it to make many quick bucks. Google responds to this illicit behaviour by banning ads.
Article Link: http://gadgets.ndtv.com/internet/news/google-took-down-1-7-billion-bad-ads-in-2016-twice-as-many-as-2015-1653413