Earlier quoted context omitted.
You don’t AirDrop cat photos to people at mass gatherings?
Isn't the default AirDrop setting to receive from people in your contact list only? (It was on my Mac and iPhone.) Probably some people change the configuration to take AirDrops from everyone, but I'd expect that to be a small minority.
All of this reminds me of good old bluejacking, which was when we did the same thing using Bluetooth.