Recently, while working at church, myself and two women were asked to make some banners. And, since these banners were over 50 feet long, they gave us a laser to make sure things were straight.
Now, the laser was about the size of a large tape measure. And, it was easy to use.
But, when we were finished, we decided to try to shut it off. Seeing a lever on the back, the woman who was using it, pushed it down. She immediately threw the laser into the air and announced that she had just been tasered!
After I examined the laser, I determined that what she thought was the off switch was really just a slide for a centering pin. In short, when she pushed down what she believed to be the off switch, she stuck herself with the built in point.