A 10-day ban imposed yesterday blocked any editing from an IP address at the US Capitol, which is shared among a number of computers.
"You have been blocked from editing for a period of 10 days for persistent disruptive editing," a Wikipedia posting said.
The move came after unusual revisions were pointed out by Twitter account @congressedits, which describes itself as "a bot that tweets anonymous Wikipedia edits that are made from IP addresses in the US Congress."
The account was created by a software developer named Ed Summers.
While Wikipedia allows users to contribute and edit entries, it also monitors for unverified or unsubstantiated comments.
A notice posted on one of the anonymous entries from Congress said, "Please refrain from making unconstructive edits to Wikipedia... Your edits appear to constitute vandalism and have been reverted or removed. If you would like to experiment, please use the sandbox. Administrators have the ability to block users from editing if they repeatedly engage in vandalism.