Earlier quoted context omitted.
I like it too, but isn't Google in a conflict of interest here?
The opposite, I would say. Google has strict guidelines for ad creative content and polices its ads as well; they're almost certainly above their own bar. So this is essentially threatening to block everyone else, or at least those behaving poorly.
Turns out it was coming from a network called Sovrn, which is ironically a member of betterads.org and apparently "recently added an extra layer of protection from malware and redirects, all of [their] creatives are pre-scanned before they are served."