Unless it's umbrellas. I probably don't understand some social custom here, but what should I call it when I leave my umbrella at the entrance and it is gone when I come back 5 minutes later...
If it's one of those clear umbrellas, it's borrowing from the common pool :)
More seriously, yes umbrellas definitely disappear very quickly, I have however noticed that the more intricate an umbrella is, the less likely it is stolen.