Google, Facebook, etc. could be the main contributors, but smaller companies would donate too (there might be a very significant long tail).
It could lobby for everything Joel talks about.
Aside from a few people at the top of Google with a sense of restraint and fair play, if Google alone decided to ruin the movie industry, they could - quickly. Obviously an IIAA pays more respect to the current way of doing things, rather than just making a unilateral decree that the movie industry doesn't get to exist anymore if they won't extend the same courtesy to the tech industry.
Slightly less drastically, I wouldn't mind Google making a note in the SERPs about which members of Congress are in favor of censoring freedom of speech. A small note with that person's position on SOPA would be a handy tool to keep the public informed.
If playing the lobbying game works, then no reason not to play.
Google bends over backwards to make sure that their rankings are entirely algorithmic so that they can retain the moral high-ground and various legal protections. It would be insane for Google to jeopardize either of those things or to risk anti-competitive and anti-trust prosecution.
Google can keep its moral highground, and the delisting is "for the people, by the people" ;-)
Do you really think that algorithms are necessarily neutral? (Hint: they're not. Consider a "hate speech" detector. It's easy to implement bias using "neutral" algorithms with "reasonable" decisions.)
Patents stuff is too confusing for me, but the concept of ad space on popular websites to spread the voice of Joel/Internet would be awesome. I think Reddit will participate because they have been pretty devoted so far, definitely not Facebook though. I dont think they want any of this drama..... asusal.