We were installing the barbed wire in the Reference area (part of a display, normally we don't need barbed wire) when one of the coils snapped back and caught me right in the center of the forehead. Yes, it bled. And as much as I wanted to get on with it, the staff insisted that I go for a tetanus shot.
I did. Probably for the best. But now you can say that you actually know of someone who was injured while stringing barbed wire in a library.