The letter was used Tuesday during a pre-trial hearing in Guantanamo, Cuba, to illustrate how all communications from people formerly held by the CIA are considered presumptively classified, The Miami Herald reported.
The presumptive classification of evidence has been a sticking point for lawyers defending five alleged terrorists linked to the Sept. 11 attacks. Attorneys contend the label has restricted their ability to defend their clients.
On Tuesday, Navy Lt. Cmdr. Kevin Bogucki told tribunal judge Army Col. James Pohl that a man held in Guantanamo since March 2008, Muhammed Rahim, sent a note to his lawyer that said only "LeBron James is very bad man. He shuld apologise to the city of Cleveland."
Bogucki said it took two months for Rahim's attorney, Carlos Warner, to have the note declassified so he could read it.
James allowed his contract to expire with the Cleveland Cavaliers in 2010 and announced he was going to the Miami Heat. Rahim's note was written two days before the Heat won the NBA championship.
Warner said he used the note to illustrate Rahim's character. In Afghanistan, where his client is from, loyalty is highly valued and "an honest apology from an offending peer is valued," he said.