Digg notes that Wikipedia started blocking the IP range owned by the US Congress, after it came out that congressional staffers had been busy, busy:

Wikipedia has recently blocked a range of IP addresses belonging to the United States Congress due to staffers who have been engaging in revert wars regarding content associated with frequent politicians. This RFC was started to centralize the discussion on the violation of Wikipedia policy and alleged libelous behavior.

This fits right in with my general take on Wikipedia (or any similar resource): content about controversial topics (which includes bios of people who are still alive and politically prominent) are going to be hard to keep objective.