The Bergan County, N.J., district attorney's office and computer Crime Unit are investigating the threats posted on a Stern fan site after Hayden criticized the Siruis radio host on a Fox News Channel, the New York Daily News said Monday.

"Howard spent a year marketing Sirius as uncensored radio," Hayden told Fox host Neil Cavuto. "There is something so unethical about this that it is making me sick."

Enraged fans started posting threatening messages on the Stern Fan Network after Stern slammed Hayden on his show, The Daily News said.

"We're not trying to stifle anybody's free speech, but it's against the law to threaten a man's life or threaten him with bodily harm," a Bergen County detective told the Daily News. "It's serious, and it's not something that can be tolerated."