Copier woes

I just don't get why a certain coworker tends to "mistakenly" take all of my printouts from the copier. It's getting really irritating. Is it a matter of being that nosy? Or is it just a form of office kleptomania? It just better stop because I dislike having to print everything at least twice. It's a waste of my time and resources.

Do you have a copier klepto?