really? 10 secs

I was staying in a hotel in San Francisco and I noticed a tray of goodies on the table. They were on a scale. If you took a goody, it would bill you within 10 seconds. I decided it was not worth trying to see if it really worked. It would have been fun though trying to trick the system. What if I put a heavy book on the scale, then ate the candy I wanted, then go and buy the candy down at Walgreens for cheaper, replace it, then take the heavy book off the scale? Would I have out smarted the system? I didn't try it, but should have.