But last week it came out that Radio Free Ohio was not a prank on Clear Channel but in fact a prank by Clear Channel. Tomorrow, an AM station the company owns in Akron will switch formats from sports talk to progressive talk, and Clear Channel would very much like anyone suspicious of corporate media to tune in.

"Once we determined we were going to change the format, we tried to get into the mindset of people who would listen to this new station," said Dan Lankford, vice president and market manager for Clear Channel in Akron. That mindset may involve a suspicion of Clear Channel itself, which has used loosened rules on media ownership to build a radio empire.

That Clear Channel owned the www.radiofreeohioorg Web site was revealed on www.stayfreemagazine.org, a magazine and blog about advertising and popular culture. Stay Free's editor, Carrie McLaren, said that she had learned the information from someone who had seen it on an Akron Web site. "In a way it's the heart of the problem with Clear Channel," Ms. McLaren said of the manifesto. " 'We're this huge corporation and we do everything to fake being local.' "

Naturally, Clear Channel disagrees. "Clear Channel, as I see it, is dedicated to entertaining radio and to getting results for our advertisers," Mr. Lankford said, noting that the company owns both conservative and progressive talk radio stations. "There's a hole in the market here and we're going to fill it."