Secretary of Defense Leon Panetta might talk to senators, but can they keep a lid on his secrets? (POOL/GETTY IMAGES)

In Spying 101, you might have learned that you needed bags of cash with which to bribe your marks, or to ply them with fine wines or lavish gifts. Not so.

Apparently, the best way to get a U.S. senator to spill the top-secret beans is to put them in front of a T.V. camera. The lure of cable-news airtime is simply that irresistible.

Yesterday, senators were treated to a hush-hush classified briefing with the top brass from the war on terror, including Defense Secretary Leon Panetta. Print media were welcome to stake out the meeting in the hopes of getting comments from senators leaving the room (after most such classified briefings, senators tend to blow off curious reporters with cryptic lines like, “it was a productive meeting.”).

But cameras weren’t allowed. Apparently, Senate leaders worried that they would “encourage” attendees to spill the top-secret information.

Could it be that senators are so enamored by the siren song of a cable-news hit (or maybe an evening news network slot, if the state secret they let slip was juicy enough!) that they would be unable to muzzle themselves?

It’s unlikely. Even the loosest-lipped senators and those most entranced by TV cameras (paging Sen. Chuck Schumer) have managed to keep sensitive details under wraps. The only slip in recent memory was in 2002 when Sen. Richard Shelby divulged some information he’d gleaned in a classified briefing. Shelby told reporters about two messages the U.S. had intercepted the day before the Sept. 11 terrorist attacks — but which weren’t translated until the day after the attacks. The leak kicked off FBI and Justice Department investigations, as well as some serious grief from a ticked-off White House.

And since when was a TV camera and a clip-on microphone a recipe for truth serum?

Besides which, it seems that the concerns about leakage were unfounded. Turns out, the meeting wasn’t all that sexy.

After the briefing, Sen. Susan Collins told a few reporters that she didn’t get what the cloak-and-dagger act was all about. “I didn’t hear anything earth-shattering,” she said, according to our colleague Felicia Sonmez. “It was a very useful briefing, but it was one of those briefings where I wonder why it’s top secret.”

“We have those occasionally,” Collins added with a laugh.