WASHINGTON (AFP) - Some National Security Agency (NSA) employees have illegally eavesdropped on the phone calls of their boyfriends, girlfriends and spouses over the past decade, the US spy service has admitted.
Confirming media reports that agency workers used surveillance technology in their private life - a practice jokingly known as "loveint" - the NSA's inspector-general, General George Ellard, released a letter to a US senator disclosing details of the romantic snooping.
The admission represented yet another setback for the agency as it struggles to defend its surveillance activities in the wake of revelations from intelligence leaker Edward Snowden, who lifted the lid on the NSA's vast digital dragnet.
Writing to Senator Charles Grassley, Gen Ellard said since 2003 there were 12 "substantiated instances of intentional misuse of the signals intelligence (SIGINT) authorities". These are procedures that allow the agency to search telephone records and tap communications of suspects abroad.
The NSA's inspector-general office had two open investigations into the misue of these powers and is reviewing an allegation for another possible probe, Gen Ellard wrote in the letter dated Sept 11. In many of the cases described in the letter, the NSA employee who acted improperly resigned before any disciplinary action was taken, and government authorities did not prosecute them.
In 2004, a female employee at NSA searched a foreign telephone number she discovered in her husband's mobile phone "because she suspected her husband had been unfaithful". She quit the agency before "proposed discipline was administered", it said.
And in 2011, another employee tried to search for call records on his home telephone number, as well as the number of his girlfriend, who was a foreign national. His request on his own number was rejected as the agency bars spying on Americans communications without a court order, but he succeeded in collecting data on his girlfriend's phone number.
He told investigators he performed the query "out of curiosity", and he retired last year before any disciplinary action had been taken.
In another case, a female foreigner working at the agency told a colleague she suspected her boyfriend at the NSA was listening to her phone calls. Her co-worker alerted the inspector-general's office, and an investigation found the boyfriend had searched nine telephone numbers of foreign women and listened to collected phone conversations while he was abroad, all "without a valid foreign intelligence purpose", the agency said.
The boyfriend was suspended without pay and resigned before any punishment was handed down.
In 2011, a female NSA worker admitted to querying the phone number of her foreign boyfriend and other foreigners she encountered.
"The subject asserted that it was her practice to enter foreign national phone numbers she obtained in social settings into the SIGINT system to ensure that she was not talking to 'shady characters' and to help mission," it said.
Civil liberties groups will point to the cases of NSA employees snooping on their lovers or spouses as further proof that the government's surveillance programme poses a threat to privacy rights and must be placed under stricter controls.
The senator whose request prompted the letter from the NSA, Mr Grassley, is asking for more information about spying abuses and urged the inspector-general to provide "as much unclassified information as possible" on the cases, his office said in a statement.