b: There's an argument to be made that if money is speech, then certainly speech itself can enjoy the same protections. Did I mention it's a nuclear option?
c: Yeah, it might. But politicians sing along to Big Content's tune because they're powerful. Reminding them, perhaps in a more delicate fashion, that "Big Internet" is also powerful and will not sit idly by while politicians help it's competitors attack them.
That's not illegal. Using a monopoly to destroy or harm the competition is. There's nothing anti-competitive in this proposal.
b) I believe the word you are looking for is Cartel rather than Monopoly, but in either case; if the bill passes they have other problems.
c) It's not a fair tactic; but there's nothing to stop Google, Yahoo, Facebook and Microsoft from coordinating on having a day where they banner link to a "Stop the power grab!" site. Singling out individual politicians is problematic.
Seriously though, as a country this whole thing is a sideshow. Our society has become too top heavy and the rights and resources have become too concentrated to the point where the average person no longer believes the social contract is for their long term benefit. That's a very dangerous place to be, and we're worried about losing access to a few cat videos?
Hell, even discussion sites like Hacker News could be affected: what if someone posts someone else's copyright content here, like a user posted the Scientology texts on Slashdot? Would YCombinator be OK with being legally responsible for the infringement? Slashdot had to take it down, but without Safe Harbor, they could've been sued.
Wikipedia, Youtube, Vimeo, Blogspot, Wordpress.com, Tumblr, you can say goodbye to all of them.
More: even if you build your own site - which is outside of the possibilities of 99% of the people in the first place - are you really safe? After all, the hosting company could be liable!
It's ultimately the destruction of the creative freedom we enjoy on the Web, converting it into TV 2.0, where all the content is created by the media companies and your only option is changing the channel.
Is that as important as being able to eat or have a place to sleep? No, of course not. But it doesn't mean it's not damn important.
Which roughly amounts to cat videos.
Nothing sinister in that - it's just like every financial institution in the world deciding simultaneously they won't deal with wikileaks donations