As online protest grows against the Stop Online Piracy Act (SOPA), you might have noticed that several websites are in the dark today. At midnight, Wikipedia users were greeted by a message explaining the black out. So what is SOPA and why does it matter? Check out this video to learn about the act and how it could impact your internet experience. Have you been affected by the blackout? Post your comments here, we'll share some during tonight's show.