A British intelligence official was fined Tuesday for leaving top secret documents on a London commuter train earlier this year.
A judge ordered Richard Jackson to pay 2,500 pounds ($3,900).
Jackson, 37, acknowledged breaking the law by failing to take proper care of the documents, which were discovered by a passenger who then handed them over to a BBC reporter.
Jackson's lawyer, Neil Saunders, said his client "accepts that he has made a terrible mistake, error of judgment, or was negligent."
Jackson was suspended after the incident, but has since returned to work in a different position. He spent much of Tuesday's hearing with his head in his hands.
District Judge Timothy Workman said Jackson inadvertently took the documents home from work on June 9 and then left them on the train the next day. Workman said he was assured that the risk of "damage to national security and international relations" was "negligible."
The documents assessed al-Qaida's vulnerabilities and the capabilities of Iraq's security forces. At least one page of the documents was stamped June 5, indicating the assessments were recent.
The security breach was the latest in a string of government data losses.