A New Jersey man will pay restitution costs of $37,500 and faces up to 10 years in jail for his part in a cyber attack on Church of Scientology websites earlier this year.
Dmitriy Guzner, 18, said he helped carry out a distributed denial of service attack that prevented others from accessing the church's website in January. This was to help further the aims of the "Anonymous" anti-Scientology group to which he belonged.
Distributed denial of service attacks stop normal access to websites by overloading them with spurious messages.
In January, at the church's request, YouTube took down a video that allegedly contained the church's copyright material, namely a speech by Hollywood actor Tom Cruise.
According to Cnet, a news organisation, the Anonymous group threatened to "expel (the church) from the internet and systematically dismantle the Church of Scientology in its present form" for abusing copyright law and stifling dissent.
The church was founded in 1953 by L Ron Hubbard. Tom Cruise is a member.
Earlier, another alleged member of Anonymous pleaded not guilty to breaking into the Yahoo mailbox of Republican presidential candidate Sarah Palin.