In a rare or perhaps even unique event, the internet banded together to fight SOPA. Large websites and communities like Reddit pitched in and the mass outcry managed to kill the maligned legislation, at least until the copyright-dependent industries come up with something new, in name at least.
In fact, that's the real problem, things like SOPA will come again, probably more often. It's going to be hard to get the same amount of support from the masses as before.
What's more is that it's going to be hard to get sites to accept a blackout or modify their content to signal the new threat.
Several of the people responsible for organizing the anti-SOPA protest are very aware of the problem and think they have a solution, the Internet Defense League
The idea is to have sites add a small script that would act as a distress beacon. Whenever the "internet" would be threatened, the script could be used to alert people and urge them to do something.