The case of the missing doorstop

Is there something I don't know about rubber doorstops? Are they some sort of magical, mystical, in-demand item? The door to my current office is weighted, so in order for me to keep it open I have to use a doorstop. Well, for ages there was a doorstop in the office. Then one day, out of the blue, the thing disappeared. So for a while I didn't have a doorstop, and then I picked one up from the supply closet. It was brand new, in the package and everything. That was last Wednesday. Yesterday I came into work and poof! The doorstop, the brand-new doorstop, was gone. It's nowhere to be found. The only folks with access to my office besides me are the housekeepers. Is it possible that they would be stealing my rubber doorstops? It makes no sense to me.