Sen. Mitch McConnell's "Bug" - Recorded Acoustical Leakage

The center of political intrigue and an FBI investigation in Kentucky's U.S. Senate race is the otherwise inconspicuous second floor hallway of the Watterson West office building in Louisville.

...behind plain, black doors is Sen. Mitch McConnell's campaign headquarters.

It is in this hallway on February 2 that two members of the Progress Kentucky SuperPAC allegedly recorded a private campaign strategy meeting underway inside an office on the other side of one of those plain, black doors, according to Jacob Conway a member of the Jefferson County Democratic Party's Executive Committee.

"You have about a half an inch gap right there where a recording device or a microphone could have been inserted," Benton said, pointing to the bottom of the door...

With the campaign's permission, WHAS11 tested whether an iPhone voice memo program could successfully record a conversation by placing the phone's mouthpiece at the bottom door opening.

Playback of the test recording confirmed that it captured the voices of campaign workers meeting behind the door. The workers had been advised of the recording test...

Some legal analysts suggest that if the closed door meeting could be heard from the hallway, the recording might not be a crime. During the WHAS11 visit, some voices could be heard, without electronic assistance, from the hallway. (more)

Imagine, two guys in the hallway listening under the door. Eavesdropping doesn't get any more basic than that. Spying tricks haven't changed, there are just more of them these days. All the old tricks still work. 

If they had their offices inspected by a TSCM team they would have been notified about the acoustical leakage vulnerability... in time to protect themselves.