Revision3 CEO Jim Louderback said MediaDefender, an ArtistDirect subsidiary formed to fight peer-to-peer piracy, caused the Web video studio’s server and site to shut down over the Memorial Day weekend through a denial of service attack.

In a blog post on Revision3’s site, Mr. Louderback said Revision3’s BitTorrent server was flooded with SYN packets of data, which caused the server, along with the site and the company’s e-mail, to shut down through Tuesday. Revision3 uses BitTorrent legally to distribute its own video content, including Web video series “Diggnation” and “Tekzilla.”

By tracing back the SYN data, Mr. Louderback was led to ArtistDirect, which confirmed the source’s address belonged to its MediaDefender company.

Mr. Louderback said he had a phone conversation with ArtistDirect interim CEO Dimitri Villard and MediaDefender VP of Operations Ben Grodsky. According to Mr. Louderback, “They willingly admitted to abusing Revision3’s network” by adding their own decoy torrent files to Revision3’s BitTorrent server, which later made it possible for MediaDefender to submit the thousands of SYN packets, as many as 8,000 per second, that caused the shutdown.

MediaDefender said on its Web site that it “uses a range of non-invasive technological countermeasures employed on P2P networks to frustrate users’ attempts to steal/trade copyrighted content.” The company achieves this by “[sending] blank files and data noise that look exactly like a real response to an initiated search request for a particular title.”

Phone calls to MediaDefender seeking comment were not immediately returned.

Mr. Louderback said the Recording Industry Association of America and the Motion Picture Association of America have previously been among MediaDefender’s customers.

He added that Revision3 suffered material losses due to the denial of service attack, which prevented it from distributing its videos and serving advertisements. According to his post, the Federal Bureau of Investigation is investigating the matter, which Mr. Louderback said is illegal in the U.S. under the Economic Espionage Act and the Computer Fraud & Abuse Act, among other laws.

Phone calls to Mr. Louderback and the RIAA seeking additional comment were also not immediately returned.