Why Has Wikipedia Gone Black?

Several websites have shut down today to protest the Stop Internet Piracy Act that is currently before Congress.

To learn more about the debate over proposed legislation that will affect internet commerce:

http://www.pbs.org/newshour/bb/media/jan-june12/sopa_01-17.html

http://www.nytimes.com/2012/01/18/technology/web-wide-protest-over-two-antipiracy-bills.html?_r=1&hp