If you try to visit Wikipedia tomorrow (January 18, 2012), you will get a black-out. They are not alone: Boing Boing, Reddit, Google and others in a NetCoalition are joining in a protest against the two bills pending in Congress currently against online piracy: SOPA (HR 3261) and PIPA (S968). Check their home pages for various forms of protest.
The NetCoalition.com website (not the .org one!) has a lot of useful information on the bills if you need to do research on this area.
Here is a nice thumbnail of the opposition to SOPA and PIPA, though you can find a LOT more out there on the net. Briefly, there is concern that the provisions are vague, allow far more over-reaching by copyright holders than the current DMCA, so that they could do take down notices to web providers, but with lots more power behind it. For instance, SOPA provides that if a web host does not immediately blacklist an accused poster on their service, the web host would then have to fight along with the poster. According to Google, more than 50% of the take-down notices it has received under the DMCA have been by businesses out to drive out competitors, rather than really about copyright issues. This is liable to be just as true in the future. Copyright take down notices are being used as an anti-competitive tool to prevent existing web businesses from having to compete against new start-ups who want to provide either a new service or better service.