A baffling theft

Someone, sometime between about 1:15 pm and 5:30 pm today came into my room and took my desk lamp away. They left the lightbulb sitting on my desk.

I'm assuming it was B&G, since my door was locked, that's a terribly odd thing to steal, and I said on my room inventory that my desk lamp did not work. You would think that they maybe could have called and left a message, or left a note, or something. Right?