It has to do with the ability to listen to the area around you. I’m not exactly sure what it’s called but there was a time people talked about “snooping on others convos” by leaving one airpod in the room and recording it in the phone. And since it’s now framed a possible listening device it violates HIPAA as you could be leaking others info. It’s a stretch but it’s somewhat logical. I used to go to cureleaf. Same thing. I had my airpod in and the security guard out front told me I had to take it out. I was confused then but I understood later that day. I thought it was for safety lol then I figured that made no sense.