The right in question isn't "to refuse ad exposure", it's to run, or not run, any arbitrary bit of code on our property, whether it serves ads, or fosters or prevents hacking, piracy, cheating, lawbreaking, unethical behavior, or antisocial behavior. Or generates kitten pictures.

Google is within their rights to want people to view ads, and even within their rights to attempt technical measures to ensure viewership. But we all have the right to circumvent those technical measures, if they're running on our property, in addition to viewing, inspecting, saving, and copying them.