First, I want to make it clear that I am against copyright infringement. It's a serious problem in need of a solution.
If you've heard of SOPA (Stop Online Piracy Act; note that links to a pdf of the actual bill), you'll know that the bill is, in theory, designed to do just that. Unfortunately, it probably wouldn't do much to actually stop online piracy (find out why not). But it would have profound implications for how we use the internet. In many ways, it would provide a broad blanket to censor social media sites.
Find out for yourself; make up your mind about it, but do so quickly. If you're against it, the time to act is now.