Using internet privacy tools, Eldo Kim, a Harvard student, send a bomb threat to his university in order to avoid taking a test. An anonymous email claimed there were a pair of explosive shrapnel-packed devices on campus.

The email listed four building that the explosives may have been placed in, one of them the building where Kim had his semester exam.

Kim is scheduled to be arraigned today. Prosecutors said that after a long search, no explosives were found. The emails were allegedly sent via the free Guerrilla Mail service, which was accessed via the Tor network.

Logs of the campus wireless network traffic were used to determine when and where a user accessed the Tor service. That allowed authorities to track the IP address back to the sender.

Kim need not be worried about his final exam. He will be too busy with a maximum sentence of five years in prison and a $250,000 fine.