Anonymous has already responded to the Megaupload.com shutdown today.
They have collaborated and taken down the official websites of the Department of Justice, Universal Music Group and the RIAA.
All these three sites are down at the moment.
Anonymous said in a statement: “It was in retaliation for Megaupload, as was the concurrent attack on Justice.org.”
They have indicated that they are working on a longer term strategy to respond to the Megaupload.com takedown.