They didn't use security cameras until pretty recently.

I had a friend that worked in one years ago. He kept his smock when he left. He'd go in and fill carts up with art supplies, just push it all out to his car. They would sell furniture in the outer entryway - tables and cabinets and things. A few times we'd back a pickup truck to the front door and just load up some furniture and take it away. Once an employee helped us load it, and thanked us.