Federal Judge Jose Linares says Jake Brahm conducted a "sick" hoax. The judge also ordered Brahm to repay $26,750 incurred in extra security costs at two of the stadiums.
The 22-year-old from Wauwatosa, Wis., says the postings were never meant to be taken seriously, but federal prosecutors argued he intended mischief.
Brahm pleaded guilty in February, admitting that he posted false information that so-called dirty bombs would be detonated at seven stadiums having games on Oct. 22, 2006.
Brahm had said the stadiums were in Miami, Atlanta, Seattle, Houston, Oakland, Cleveland and New York City. He admitted that the reference to New York City was intended to indicate Giants Stadium, in East Rutherford, N.J., where the New York Jets played the Detroit Lions that day.
The threat, dated Oct. 12, 2006, appeared on the Web site "The Friend Society," which links to various online forums and off-color cartoons. Its author, identified in the message as "javness," said trucks would deliver the bombs to the stadiums.
The posting added that the stadium explosions would be praised by Osama bin Laden as "America's Hiroshima" and spark global conflicts.