I was talking with an employee at a grocery store, who told me that management one day decided to review the surveillance footage, and fired a bunch of employees who were caught pilfering.
I had a friend who was a checker at a large local chain, and before shift one day he popped into the security office (he was friends with the head of security) to say hi, and they had every camera in the front of the store trained on the employee working the customer service desk.
I'm not in the least surprised. People steal from businesses routinely, it's all part of the anti-business mentality.
Case in point - one time the cash machine on the bank exterior disbursed an extra 20 to me. I counted it carefully, sure enough, an extra one. So I went around to the other side, went in, and handed it to the teller with an explanation. She about fell over in shock.