Someone Left This On My Desk...Would You Eat It? [POLL]

Yesterday I found a treat placed on my desk from a mystery person. I went around the building and asked nearly everyone I could find if they were the culprit. No one fessed up and it's making me a little paranoid. I'm on a diet and wouldn't eat the treat anyhow, but at the same time I really want to get to the bottom of this!

Here's what I know;

Someone left food on my desk yesterday between 11:30 a.m. and 1 p.m. I have no idea who it was.
I found a cookie sandwich inside of a container that was placed inside of a plastic bag.
The container doesn't have a seal on it...but it does have an expiration date of March 17.
I'm on a diet, so it's either someone I know trying to play a joke on me...or someone that I don't know. If it's someone I don't know then it makes this situation a little more sketchy.

So, knowing what I know, would you eat the random treat? Have you ever eaten something given to you by a stranger or unidentified person?