I don't know if that's true that it's an abuse of their position. Here's the paragraph from their policies:
> Sites showing Google ads should be easy for users to navigate. Sites may not change user preferences, redirect users to unwanted websites, initiate downloads, include malware or contain pop-ups or pop-unders that interfere with site navigation.
That all seems reasonable to me. They don't want to be associated with garbage websites.
> Sites showing Google ads should be easy for users to navigate. Sites may not change user preferences, redirect users to unwanted websites, initiate downloads, include malware or contain pop-ups or pop-unders that interfere with site navigation.
That all seems reasonable to me. They don't want to be associated with garbage websites.