Wikipedia administrators have imposed a ban on page edits from computers at the US House of Representatives, following "persistent disruptive editing".
The 10-day block comes after anonymous changes were made to entries on politicians and businesses, as well as events like the Kennedy assassination.
The biography of former US defence secretary Donald Rumsfeld was edited to say that he was an "alien lizard". One staffer said they were being banned for the "actions of two or three".
Edits from computers using the IP address belonging to the House of Representatives have been banned before, following similar acts of vandalism.
The latest block comes after rogue edits were brought to light by a Twitter feed, @congressedits, which posts every change made from the government-owned address.