Here are a few plots and data I collected for the SOPA blackout from 18 January. Wikimedia Foundation is working on a wider coverage of the event.
The huge dip in CongressLookup hits on the first day was during hours where most US citizens were asleep. Of course the CongressLookup page did not make much sense for non-US citizens.
Here is a list of most visited SOPA related pages on different Wikipedias during the blackout (24 hrs only).