Atlanta ? Wikipedia, the online encyclopedia that can be altered by anyone with a computer, has proved useful for pulling political dirty tricks.

Political operatives are covertly rewriting – or defacing – candidates’ biographical entries to make the boss look good or the opponent look ridiculous.

As a result, political campaigns are monitoring the Web site more closely than ever this election year.

Revisions made by Capitol Hill staffers became so frequent and disruptive earlier this year that Wikipedia temporarily blocked access to the site from some congressional Internet addresses. The pranks included bumping up the age of the Senate’s oldest member, West Virginia’s Robert Byrd, from 88 to 180, and giving crude names to other lawmakers.

In Georgia this week, the campaign manager for a candidate for governor resigned amid allegations he doctored the Wikipedia biography of an opponent in the Democratic primary.

Morton Brilliant was accused of revising the entry for Lt. Gov. Mark Taylor to add his son’s arrest in August in a drunken driving accident that left his best friend dead.

The information was accurate and had been in the news. But Brilliant’s boss, Georgia Secretary of State Cathy Cox, declared the son’s legal troubles out of bounds.

The link to Brilliant was discovered by Taylor’s campaign, which accused the Cox camp of engaging in “gutter politics.”

Some 1,000 volunteer monitors scan changes to Wikipedia’s entries to keep them free of obvious partisan editing, factual errors and profanity, said Wikipedia founder Jimmy Wales.