A computer programmer was sentenced Friday to two years in prison for using a botnet made up of 100,000 computers to retaliate against websites that published an embarrassing article about him, including Rollingstone.com and Radaronline.com.

Bruce Raisley, 48, of Kansas City, Missouri, was arrested two years ago after launching a series of attacks that knocked nine websites offline between 2007 and 2008.

A former volunteer with the pedophile-hunting group Perverted Justice, Raisley had had a falling out with its founder, Xavier Von Erck, and became an "outspoken critic", the Department of Justice said Friday in a press release. Perverted Justice is best known as the organisation that helped conduct sting operations for the Dateline NBC program "To Catch a Predator".

The feud between Von Erck and Raisley was personal and it was public. Ultimately, for Raisley, it was humiliating.

Raisley was trying to pressure websites into removing Rolling Stone and Radar Online stories about Perverted Justice that chronicled a particularly nasty episode in the feud between the two men, prosecutors said. Other sites, including Rickross.com and Corrupted-justice.com, were hit because they republished these two articles.

Von Erck "exacted a particularly sadistic form of revenge" against Raisley, according to the July 2007 Rolling Stone article about the group. Posing online as a woman named Holly, Von Erck convinced Raisley to break up with his wife. When the programmer, flowers in hand, went to pick up Holly at the airport and start their new life together, Von Erck had a friend take a photograph and posted it online, writing: "Tonight, Bruce Raisley stood around at an airport, flowers in hand, waiting for a woman that turned out to be a man ... He has no one".

Prosecutors say Raisley targeted nine sites in total. Rollingstone.com, for example, was attacked between July 2007 and March 2008. At one point, its Perverted Justice article was getting millions of downloads per day from Raisley's botnet, prosecutors said.

It cost the nine websites more than $100,000 (£61,370) to fight the attacks.

Raisley was found guilty by a jury following a six-day trial in September 2010. He was sentenced Friday in US District Court for the District of New Jersey.

Following his two-year prison sentence, Raisley must serve three years of supervised release. He must also pay more than $90,000 (£55,555) in restitution to his victims.