It might be because you told everyone where you keep your bananas. If I worked at your office, I would swipe them too seeing as it irritates you. Maybe you should keep your bananas in your apartment fridge and bring them in each day.
get a marker and write on your banana...touch my banana and you'll see this up your other pie hole.
In some cultures, having your bananas stolen is a sign of great respect.
i hate when i have problems with my banana