Patriotic 'Hacktivist' Claims He Took Down Wikileaks Site Hacker-activist 'The Jester' also says he attacks jihadist websites.

Nov. 30, 2010 -- A computer hacker is claiming he temporarily disabled the Wikileaks site Sunday afternoon, right as the latest dump of leaked State Department memos were scheduled to publish on the site.

The site was down temporarily on Sunday, the same time the hacker began tweeting he had begun attacking it.

"www.wikileaks.org - TANGO DOWN - for attempting to endanger the lives of our troops, 'other assets' & foreign relations," he tweeted late Sunday morning.

"Tango down" is a special forces military term for having eliminated a terrorist.

He goes by the Twitter handle "th3j35t3r", which is leetspeak for "The Jester."

On his website, th3j35t3r calls himself a "hacktivist for good." A "hacktivist" -- a hacker-activist, supposedly hacks for a good cause. His cause is preventing young people from being recruited online by jihadists. He does this by hacking jihadist websites, and temporarily disabling them.

"PS for me personally WL is a sideshow target, I am more interested in the big jihad recruiting and training sites," he said Sunday in a direct message to ABC News via Twitter, referring to hacking the Wikileaks website.

Mikko Hypponen, chief research officer of global information technology security software vendor F-Secure, said today that he's familiar with The Jester.

"I don't know this guy, I've never met this guy, I've been running into his attacks because he is fairly visible unlike other attackers, because he documents his attacks, runs his own blog, also tries to explain his motives and reasoning behind the attack," he said. "I've only seen him do denial of service attacks."

Hypponen said today that there's no proof that The Jester is behind the Wikileaks attack. "But he's demonstrated the capability to do an attack like this. He seems to have the motive against Wikileaks, and he claims he did it. I don't think there is much reason to doubt that it was him."

"Wikileaks is being attacked right now, starting three hours ago, and The Jester is being silent so we don't know if the attacks are being done by him or someone else."

ABC News conducted an exclusive interview online with a person calling himself The Jester last month, during which he revealed details of how he takes down sites, and why he does it.

He says the reason he takes down jihadist websites is "multi-fold."

"big thing is the fact that we waste billions on troops risking their lives in the field (hats off)" he writes.

"but the real threat now is the way they can radicalize 'normal' muslims into doing awful stuff on their own countries ground..." he continues, "they can groom. recruit, train, and manourvre, home grown terrorists without ever having to meet them."

He says his aim was "initially to make those sites sporadically unavailable," yet he did not want to tread on the toes of countries' secret services. He says he used an attack tool he developed, "XerXeS", which will "pull down a site at will."

He claims to be a former member of a special operations unit, but provided no details. He says he has worked with U.S. forces, and has the "utmost respect for their conduct in the field."

Wikileaks Hacker Explains Attack Strategy

And while he will not disclose whether he has ever fought in Afghanistan or Iraq, he was involved in the "business of closing and destroying the enemy, up close and personal."

"just rest assured -- Jester is a freind of US," he writes.

He says he has taken down more than 179 jihadist websites with U.S. servers.

"US still have no idea where they come from," he writes. "they know it is J," he writes, referring to himself. "but not who J is."

th3j35t3r said he only takes down sites for 30-60 minutes.

"I could pull them down forever but i choose to do sporadic bursts," he says, so that authorities will either be alerted to the hacked website, and so they can continue monitoring its visitors if they had been doing so already.

He says he has a strategy to his hacking.

"I hit some sites a lot and other sites not so much," he says. "this is a tactic by hitting one site less it herds the target of these sites into it where they are easilt monitored, its easier to monitor a smaller space."

What keeps th3j35t3r from abusing his hacking abilities to harm U.S. interests?

"my dead friends kep me from dong that, and also my alive ones. ;-)," he writes back. "and my drive and reason for embarking on this in the first place."

Wikileaks Hacker Wishes to Remain Anonymous

He has plenty of fans online, illustrated by the replies and retweets he gets on Twitter.

One person tweets: "Thanks Jester for doing Obama's job", and another: "There should be more people like you around!"

Yet he has detractors, too.

"#wikileaks is the only thing keeping us from living under a fascist regime. the only ppl they've harmed are corrupt politicians," one person tweeted.

th3j35t3r says he wishes to remain anonymous, and turns down TV interviews. Nevertheless, he has become an underground celebrity among techies, and has been interviewed by tech blogs.

"I am not about the limelight," he writes, "I am about the issue."

He will not confirm his nationality, location, age or occupation, but will talk about how he got into hacking.

He says he is under 50-years-old and over 30, and began coding when he was 10 years old. He says he was "thirsty for knowledge about how computers worked, and fascinated by the fact that just a guy and a keyboard might make a difference to something."

However, he says he was "always drawn to applying myself withiin the military," and thus, did his time as an airborne frontline combat trooper, twice.

th3j35t3r says he isn't targeting Muslims -- just those who try to recruit terrorists online.

In the past two years over 60 Americans have been arrested or convicted on terrorism charges, including some who made contact with jihadist recruiters online.

"I have no problem with muslims, I have many muslim friends who would if they knew support me. It's the online grooming, recruiting, training and tasking I have issue with," he writes. "I wouldnt say I am a protector of muslim youth particularly, thats hopefully a by-product."

"islam isn't the issue," he says. "radical islam is."