...having a camera right in a customer's face would generally be a negative.
Ditto for a "powerful microphone" in a customer's face.
But even worse is when it's not in your face, say you are 2nd or 3rd in the bank line, and you and your SO are unaware that your discreet discussion about your finances is being monitored/recorded and analyzed.
So I think some sort of major disclosure would be necessary there. Adding to the chilling effect.
Maybe they could equip the thing with a "powerful sound sensor" instead of a microphone, capable of capturing intensity without enough resolution to decipher conversations. But then so much for the Manager coming up to speed on the situation quickly.
An overt camera doesn't mean people are aware that audio is being recorded in any effect, so I wonder what it says in their terms and conditions...
No doubt something like, "check your local laws" and don't do anything illegal...