Personally I think blacking out websites, tweets and photos isn't the best way to protest something that could do exactly that - better to go out and make and share content showing what is possible now and explain how that might go away.
Which is what this video by Kirby Ferguson1 does a great job of. Explain what's at stake
Direct link to video
SOPA and PIPA are American issues now but if enacted would certainly affect us all a great deal. And there's a pretty good history of Canada attempting to simply follow along with the entertainment/government of the USA so it's a good idea to be informed about what's going on down south.