Dec. 1, 2010 at 2:43 PM ET
Update 3:15 p.m. ET: WikiLeaks tweets confirmation that it has been booted from Amazon.
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Whoever wants to bury the WikiLeaks documents is doing a better job today — apparently with an assist from Amazon.com.
The subsite hosting the classified State Department documents (cablegate.wikileaks.org) has been under attack since shortly before it started publishing the documents Sunday. While access to the site has been spotty, WikiLeaks had been more or less able to withstand the attacks until this morning, when it became completely unavailable.
The site was down for several hours before returning erratically about 2:15 p.m. ET.
The attack is what's known as a Distributed Denial of Service, or DDoS. A group of computer users or an organization distributed across multiple systems floods the host's servers with spurious requests for access, overwhelming the target so that it can't repond to anybody's request. It's the same strategy that's been used in previous high-profile attacks, notably the assault by the shadowy Internet collective Anonymous, which took down the Church of Scientology's site for several days in January 2008.
Here's a good Wikipedia explainer on DDoS attacks.
What's notable about today's attack is the scale. WikiLeaks tweeted this morning that the attack was "exceeding 10 Gigabits a second" — two to five times as large as the initial attack on Sunday. (Arbor Networks of Chelmsford, Mass., which monitors and protects companies against DDoS attacks, analyzed Sunday's attack here.)
Another way to think of it is that someone, somewhere is demanding that the WikiLeaks cablegate site deliver the equivalent of 114 movies per second. That's about 50 times the size of the attack that took down Scientology.
That's a massive attack, but it's not as big as some it has survived in the past. So why did it have so much trouble today?
As Wired.com recounts on its Threat Level blog, the volunteer who set up the site's defenses was among a number of WikiLeaks volunteers who quit in September in a dispute with founder Julian Assange. They took their software with them.
It's never been made clear what WikiLeaks replaced it with, but it is known that the site has been redirecting its addresses through cloud-based services, one of which, beginning over the weekend, was Amazon Web Services. Today, Sen. Joe Lieberman, I-Conn., a harsh critic of WikiLeaks, said in a statement (printed in full on Talking Points Memo) that Amazon had agreed to "cut off WikiLeaks."
The Associated Press reported that WikiLeaks returned to its regular Swedish provider after Amazon dropped it.
Amazon wouldn't comment, and WikiLeaks spokesman Kristinn Hrafnsson didn't respond to a request for comment.
Alex Johnson is a reporter for msnbc.com. Follow him on Twitter and Facebook.