While scrolling the web I came across this...
Whoa
Upon further review, it's legit.
To clarify, "Live Listen" wasn't made for eavesdropping; it's actually an accessibility feature that allows people who are hard of hearing to use AirPods to enhance sounds and voices around them.
The use is limited to Bluetooth range, so you can't leave your phone at home and then go to work, or wherever, and expect to still hear anything.