Why is there no Wikipedia today?

If you try to go to Wikipedia, or dozens of the most popular sites out there, you're going to find them blacked out today (Wednesday, January 18, 2012). If you don't know why--and you don't know what SOPA or PIPA mean--you should find out. Many are saying that these bills in the Senate and House would, if passed, put an end to what's left of the free and open Internet, and even open the door to censorship. Find out more at http://en.wikipedia.org, or https://www.google.com/landing/takeaction/.