The Great Wikipedia Protest Blackout of 2012 did not result in any particularly significant increase in site searching at the University of Michigan Library. While traffic was up on January 18, 2012, over the same day the previous week (January 11), the increase was about the same as for the day before and the day after -- reflecting the increasing workload of the academic semester more than any Wikipedia-inspired bump.
January 18 compared to January 11, 2012
Here are some numbers to illustrate the point. For "Outage Wednesday" compared to the previous Wednesday (January 11), searches were up slightly: 4% overall, and 14.5% for the default default "MLibrary" site search:
January 17 compared to January 10, 2012
However, a somewhat larger overall increase is noted between the Tuesday before (January 17) and the Tuesday a week earlier (January 10): up 9% overall and 10% for the default "MLibrary" site search:
January 6-12 compared to January 13-19, 2012
For a 7 day week extending from the Friday before the outage to the Thursday after, when compared to the previous week, we see an actual decrease in Outage Week over the week before (a decrease of 2.45% overall, although a small 2.2 percent increase in the default "MLibrary" site search: