A group of hackers calling itself "Anonymous" has hit the Church of Scientology's Web site with an online attack.

The attack was launched Jan. 19 by Anonymous, which is seeking media attention to help "save people from Scientology by reversing the brainwashing," according to a Web page maintained by Anonymous.

Anonymous claims to have knocked the Church's Web site offline with a distributed denial-of-service attack, in which many computers bombard the victim's server with requests, overwhelming it with data in the hope of ultimately knocking the system offline. True to its name, Anonymous does not disclose the true identities of its members.

The attacks were spurred by the Church's efforts to remove video of movie star Tom Cruise professing his admiration for the religion, according to an Anonymous video manifesto posted to Youtube.

"For the good of your followers, for the good of mankind and for our own enjoyment, we shall proceed to expel you from the Internet and systematically dismantle the Church of Scientology in its present form," a creepy computerized voice states in the video. Anonymous followed up this dispatch with a second video blasting the media for failing to completely report the group's criticisms of the church. This video was taken down Friday by Youtube, citing a "terms of use violation."

Anonymous has managed to generate a measurable attack against the Scientology.org Web site. Over the past few days, the site was hit with several DDOS (distributed denial-of-service) attacks, which flooded it with as much as 220M bps of traffic, according to Jose Nazario, a senior security engineer with Arbor Networks, whose company compiles data on Internet attacks.

The Anonymous campaign shows some level of organization. "220M bps is probably about in the middle of attack sizes," Nazario said. "It's not just one or two guys hanging out in the university dorms doing this."

On average, the attacks lasted about 30 minutes and used up 168M bps of bandwidth. In the past year, Arbor has seen attacks on other sites hit 40G bps, or 200 times the strength of the Anonymous event.

Shortly after it was hit with the DDOS flood, the Scientology.org Web site was moved to a server hosted by Prolexic Technologies, according to data compiled by Netcraft, an Internet monitoring company. Prolexic specializes in protecting companies from DDOS attacks.

A Prolexic spokeswoman confirmed that the Church of Scientology is one of the company's clients, but declined to offer more details on the matter. The Church of Scientology did not answer questions relating to the online attacks, but in a statement it said that the controversy over the Tom Cruise video had driven traffic to its Web site.

The secretive Church of Scientology's practices, including its efforts to use copyright law to restrict the dissemination of information about the church, have engendered a lot of criticism within the Internet community. But one Web site set up to criticize Scientology -- called Operation Clambake -- called the DDOS attacks a bad idea. "Attacking Scientology like that will just make them play the religious persecution card," wrote Andreas Heldal-Lund, the Web site's owner. "They will use it to defend their own counter actions when they try to shatter criticism and crush critics without mercy."

If publicity was Anonymous' ultimate goal, the group has had some success. Late in the day Friday, seven of the top 10 stories on the Digg.com news-linking site related to Scientology or to Anonymous' communiques.

Although the group's Web page exhorts participants to "begin bumping Digg," Anonymous did not manipulate the news site's promotional algorithm system, which determines which stories get top billing, according to Digg CEO Jay Adelson.