I'm not sure if you're talking about police or the bank. In either case, what difference does it make if there is a vast array or one or more itinerant scammers? It is still their problem. The clowns are supposed to arrest criminals and the banks are supposed to identify violators of their security to the clowns. When did this become a matter for vigilante inquiry to determine whether somebody went did something bad or something?
You indicate that there has been a systematic theft using bank protocol. Both the bank and the police have a responsibility at the time when you file the complaint. I'm confused...