I'm sure you'll run across this yourself at some point (25 million wikipedia hits a day after all), but just wanted to point it out for some of the non-Americans too.
I don't think the Google black line on their logo will do much, but wikipedia being dark should have some people take notice. Whether it will get people to take action is a different problem, as we've seen before. But it seems to be a much more relevant and directed kind of protest at least.
Here's a summary of the issue.