Brian Dean Miller was apparently upset over the new health care law. A criminal complaint says the 43-year-old man admitted to a Secret Service agent that he threatened to kill the president in a post on Craigslist March 21.
Calling for a revolution, the post in part reads: "I am dedicating my life to the death of Obama and every employee of the federal government."
Agents subpoenaed Craigslist and AT&T to track down the originating e-mail address.
Agents arrested Miller and seized his computer March 25. They found no weapons at his home.
If convicted, Miller faces a maximum five years in prison and $250,000 fine.