Why don't banks (like gas stations) put up bulletproof gl between Teller & Customer to prevent burglaries?

Although more banks are going that direction, I don't think it will solve their problem. Banks are responsible to not only protect your money and their employees, they are also responsible for the safety of their customers. If the bank is being held up and the customers are being used as hostages, I believe that the bank would be required to meet the demands of the criminal in the same manner as if the teller was the one at risk. It will be interesting to see if banks follow the same direction as the airports, forcing us all to go through metal detectors and body searches in the future! The inmates have taken over the asylum!!!!!!!!!!!!!! Just a thought.