The CIA is subjecting operatives working in Libya to polygraphs as much as once a month to stop them from leaking to the press or Congress about Benghazi, CNN's Jake Tapper and Drew Griffin report. Usually, CIA operatives are polygraphed only once every three or four years.  "It is being described as pure intimidation, with the threat that any unauthorized CIA employee who leaks information could face the end of his or her career," CNN reports. The CIA told CNN that it has been cooperating with congressional oversight committees and "CIA employees are always free to speak to Congress if they want."

The story suggests the CIA wants to keep its operations in Benghazi secret, not specifically what happened the night of the attacks. It was not until weeks after the Benghazi attacks that it was reported the diplomatic facility there was mostly a CIA operation. Two former Navy SEALs who died during the attack were reportedly CIA contractors. Now CNN reports that 21 people were working at the CIA annex on the night of the attacks, while a total of 35 people were working at the mission. (This tracks with estimates in earlier reporting.) What were they doing there? That's been the subject of much speculation for months. In March, Sen. Rand Paul floated the theory that the Obama administration was covering up a gun-running operation to arm Syrian rebels. In May, Paul speculated on CNN. "I’ve actually always suspected that, although I have no evidence, that maybe we were facilitating arms leaving Libya going through Turkey into Syria."

The CNN report offers a nod to that:

The State Department told CNN in an e-mail that it was only helping the new Libyan government destroy weapons deemed "damaged, aged or too unsafe retain," and that it was not involved in any transfer of weapons to other countries.

But the State Department also clearly told CNN, they "can't speak for any other agencies."

On Thursday, House Oversight Committee chair Darrell Issa subpoenaed more State Department documents related to Benghazi. Issa is seeking interviews and documents collected by an independent review board. The initial focus of the Benghazi controversy was who wrote the talking points for then-U.N. ambassador Susan Rice to use on five Sunday shows after the attacks. But as Paul's comments show, the controversy seems to be evolving.