WBIR-TV, Knoxville, reported agents served the warrant at the residence of David Kernell, 20, son of Mike Kernell, a Democratic state legislator from Memphis, ComputerWorld magazine said.

Palin, the Republican U.S. vice presidential nominee and Alaska governor, had her Yahoo Inc. (NASDAQ:YHOO) e-mail account hacked, and someone identified only as "Rubico" was linked to the attack after posting a message claiming to have accessed Palin's account by using Yahoo's password reset feature, the magazine said.

A witness told WBIR-TV that the agents spent nearly two hours searching Kernell's apartment, adding that Kernell's roommates were also subpoenaed and must testify this week in Chattanooga, Tenn., Computerworld reported.