That's where the question gets interesting! Your browser definitely (under current laws) has the right to refuse to allow NoScript to run, so if a similar program specifically targeted google ads then chrome would not be obligated to support it and could use the laws around your legal right (and lack thereof) to proprietary modify software to order you to cease & desist running it.

I think that websites do, legally, have the right to refuse you service if you run NoScript and some websites go through crazy hoop to exercise that right. I _suspect_ that using NoScript to alter the page is actually illegal under current intent since that usage could cause the software to misperform and potentially cause damages and it violates the agreed upon usage contract on that site. That said, it's _mostly_ unenforceable on a technical level (usually it's at least not cost effective to do) and I personally think it's unethical to force people to run malware to view your content - it needs a clearer definition in the law though, all this stuff is stupid hazy.