Here's an idea: Google, Twitter, FaceBook, Amazon, etc. all slow traffic to their sites, along with a clickable notice at the top suggesting they take action to prevent future slowdowns.
So they will lose god knows how much revenue, piss off their customers, and get a tiny fraction of people to 1) actually click the banner 2) read all those scary words 3) actually understand and get angry about the implications.
If it's a coordinated effort it will resonate. It's risky, but the best way to bring attention to the issue. In the long-run, it would cost less than allowing Comcast and others to practice legal extortion.