Someone at work had taken to stealing food and drinks out of other peoples bags a year or 2 back.
The site I work at is quite big and has around 130+ people on site at any time.
We have this huge bank of fridges in the canteen are where people store their food and this is where it was going missing from.
I only had a couple of cans of coke taken out of my bag, but a friend of mine had his scran nicked on a couple of occasions.
Once they had his bowl of scouse off, cleaned the container it was in (!!!!)
and put it back in his bag lol
Sick of it by this point, he
bought a tin of cat food, spread it on some sandwiches, wrapped them in cling film and left them in his bag.
They were taken a couple of days later. Strangely enough nothing went missing again after that