Los Angeles , California ( CNN ) -- A Nebraska man is expected to plead guilty next week to launching a cyber attack that shut down the Church of Scientology 's Web sites , federal prosecutors said Monday . Brian Thomas Mettenbrink , 20 , of Grand Island , Nebraska , was accused of participating in an attack orchestrated by a group that called itself `` Anonymous . '' The group led protests against the church in various parts of the country before announcing in January 2008 that it would launch a cyber offensive , said Thom Mrozek of the U.S. Attorney 's Office in Los Angeles . Mettenbrink admitted in court that he downloaded software from an `` Anonymous '' message board and used it to launch `` denial of service '' attacks on Scientology Web sites . In such attacks , hackers flood a target site with so much traffic that it is unable to handle the volume and slows to a crawl or crashes altogether . As a result , the site is then unavailable to legitimate users . The group targeted the church after it forced Web sites to yank a leaked video of actor and church member Tom Cruise fervently making the case for Scientology . The video was intended for attendees at a church award ceremony in 2004 where Cruise was being honored . `` We are the authorities on getting people off drugs , we are the authorities on the mind , we are the authorities on improving conditions ... we can rehabilitate criminals , '' Cruise says in the video . In 2008 , the video was leaked online and widely ridiculed . The church responded by threatening to sue Web sites unless they removed the clip . `` Anonymous '' then launched its attack . As part of its offensive , the group asked Internet users to not only download the `` denial of service '' software from its message board , but also to place prank phone calls , post proprietary church documents online , and send black pages to church fax machines to waste ink . The group posted a YouTube video that said it aimed to `` expel Scientology from the Internet . '' `` Expect us , '' the video ended . The attacks targeted local and global sites of the church . Mettenbrink is expected to plead guilty in federal court next week to a misdemeanor charge of accessing a protected computer with authorization . He agreed to serve a year in prison , Mrozek said . Mettenbrink 's is the second successful prosecution connected to the `` Anonymous '' attacks . Last year , Dmitriy Guzner of Verona , New Jersey , was sentenced to a year and a day in federal prison for attacks on Scientology sites . The Church of Scientology , founded by the late science fiction author L. Ron Hubbard , is well known for its high-profile , celebrity members . In October , film director Paul Haggis left the church for its alleged public support of Proposition 8 , which eliminated the right of same-sex couples to marry in California . Also in October , a French court convicted the church and six of its leaders of organized fraud . The court imposed fines totaling more than $ 1 million on the church and the convicted staff . The plaintiffs focused their complaints on the use of a device that Scientologists say measures spiritual well-being . Members used the electropsychometer , or E-Meter , to `` locate areas of spiritual duress or travail so they can be addressed and handled , '' according to Scientology 's Web site . The plaintiffs said that , after using the device , they were encouraged to pay for vitamins and books . They said that amounted to fraud . The church has called the decision a `` modern Inquisition '' and said it would appeal the verdict .
Nebraska man admits role in attacks on Scientology Web sites . He downloaded and used software to launch `` denial of service '' attacks . He is expected to get a yearlong prison sentence .