What happened to my cardboard automata?

During the prototyping phase, I created several cardboard automata. I found out today one of them was gifted to a visitor. Although it was put up along with the others the students had created, due to lack of storage space, they were placed in a location whereby visitors could see them. While I was away last week, a young visitor beheld one of my cardboard automata, and asked if he could have it, to which one of our newer staff personnel complied.:-(

Greg