A labelled yogurt is cool. But we constantly have people eating other people's yogurts because nobody labels them and people think they are grabbing their own, not remembering what flavour they brought.
Not an issue for me - I can't stand the stuff! I kept trying but I couldn't find one I liked. I've given up.
Someone once grabbed a yogurt out of our office fridge. Took one huge spoonful and then started gagging. Then, when he could talk again, he accused "somone" of planting deliberately foul-tasting yogurt in the fridge. You know, the way sometimes people suggest putting hot sauce in food to foil fridge thieves?
Only it was my yogurt, properly labeled with my initials. And it was perfectly fine. He'd just never tasted plain, unsweetened yogurt before.
At one workplace, we low-paid admin staff were continually getting our milk etc stolen by the highly-paid lawyers. That stopped after we started putting various colours of food dye in it.
At a different workplace, I had a jar of sweets on my desk. I had no problem with sharing them if people asked - that's why I had them visible - but I did
have a problem when the level started mysteriously going down whenever I left my desk. So I took steps.
I would like to point out that I actually really like the sweets I filled my jar with... Atomic Fire Balls ( http://www.oldtimecandy.com/atomic-fire-balls.htm
). They are awesome! They taste like cinnamon and heat and sweet, sweet pain. And if you take all their individual little wrappers off before putting them in a jar, they look
just like Jaffas ( http://en.wikipedia.org/wiki/Jaffas
)... which the suspected culprit liked. He did NOT like hot things. Sadly I was absent with a tummy bug when my candy jar was next raided, but it never happened again!
[Insert disclaimer noting that I definitely do not condone or suggest spiking or booby-trapping foodstuffs with anything that is dangerous, an allergen, or not a normal food ingredient. Perfectly normal and safe food that a lot of people don't like, on the other hand, is fair game. I recommend nattou for severe cases of food thievery.]