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.
Surprising how common it is. The first hardware I ever designed on the job was a device to detect employee theft.
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.
Someone got fired that day.