Attorney-client privilege is a bedrock legal principle.

But on Monday, a U.S. military commission released a photo of what appeared to be an ordinary smoke detector on the ceiling of a room where attorneys met with terror detainees at Guantanamo Bay, Cuba.

The smoke detector was actually a listening device that could have been used to eavesdrop on conversations that were supposed to be private.

But the Miami Herald reported that one of the top military lawyers for the Gitmo detention facility said he looked into the matter as soon as he learned about it and found that no one was listening in on privileged conversations.

A military judge hearing the case against accused 9/11 mastermind Khalid Sheikh Mohammed and four others ordered the photo released.