A federal appeals court overturned on Friday a Washington state man's conviction for possessing and distributing child pornography because he was found out by a military investigator.

A Naval Criminal Investigative Service agent used a high-powered software program in 2010 to search computers throughout the state of Washington for evidence of child pornography and discovered the material in Michael Dreyer's computer.

The agent passed the information on to police in Algona, Washington, which obtained a search warrant and searched Dreyer's house. The Department of Homeland Security later got a federal search warrant, and Dreyer was charged in federal court.

When the search was challenged, the government argued that the search was justified because there are military bases in the greater Seattle area, and it's a crime for military members to distribute child pornography.

A panel of the Ninth District Court of Appeals in San Francisco said the computer surveillance didn't target military bases or personnel, but extended across an entire state.