The Electronic Frontier Foundation (EFF) has come to the aid of a liberal blogger whose website was taken down after a radio station complained that critiques containing on-air clips violated its copyright.

Spocko, the anonymous blogger posting at Spocko's Brain had his website shut down earlier this month after ABC, the parent company of San Francisco radio station KSFO, sent a cease-and-desist notice to his web hosting company. Spocko's Brain reappeared when he signed up with a new web hosting company.

The EFF threatened a lawsuit against ABC and KSFO if they further attempted to shut down Spocko with Digital Millennium Copyright Act threats. "ABC/KSFO's complaints amount to nothing more than an attempt to silence an effective critic," EFF lawyer Matt Zimmerman wrote. "EFF ... will vigorously defend Spocko against misguided efforts to limit his First Amendment rights."

Spocko's use of KSFO clips for criticism does not violate copyright law, Zimmerman said in his letter to ABC. Spocko's use of the clips are protected by the legal doctrine of “fair use”, allowing the use of copyright works for criticism, news reporting and research, he said.

Spocko, who's been complaining about KSFO since 2005, has urged advertisers to stop supporting the station because of commentary on the talk radio station he says is offensive. Some advertisers have pulled their ads, according to information published on his blog.

He has recently complained about comments by KSFO talk-show hosts disparaging the ethnicity of a US senator, as well as inflammatory remarks by show hosts regarding Muslims and the suggestion that a newspaper editor should be executed.

KSFO didn't respond to an email requesting comment, but KSFO hosts, in a programme on 12 January, said in some cases, liberal bloggers were complaining about radio bits that were obviously jokes. In other cases, hosts apologised for offending some people, the hosts said.

KSFO needed to strike back against liberal bloggers because of the "unlimited scurrilous tactics they are willing to use to silence anybody with which they don't agree”, Rogers said in the 12 January broadcast. Liberal bloggers have violated copyright law by taking quotes "out of context”, he said.

But the EFF and Spocko argued that it was the radio station trampling on freedom of speech, not the blogger. Spocko, responding by email, said he was the one who was shut down. "The radio hosts are crying that I'm trying to silence them, but the one who had the real power (them) acted," he wrote. "They used bogus copyright claims to silence me."