Yet another horribly dangerous construction tool.
To clarify, the Senco Air-Nailer is a very safe tool, using compressed air to drive nails, simplifying and speeding up modern construction. For safety, the gun has both a trigger and a safety bail, which is a movable wire frame around the head of the gun which prevents it from discharging unless the gun is in contact with a solid surface -- or if the bail has been wired up, simulating permanent contact with something solid. This will allow the gun to discharge every time the trigger is pulled. Bored construction workers in crowded sub-divisions are sometimes seen shooting nails into the walls of nearby houses using guns with this modification.
Even more dangerous is taping up the trigger. This allows the gun to discharge every time the gun is pressed against a solid object. This can really speed up construction, and lead to some real fun.
I watched a friend of mine on a job shoot a 16 penny nail into his thigh, all the way into the bone, with his nailgun. That slowed things down on the job, but not as much as what happened a couple weeks later on another site that I wasn't on.
One framer had just finished building a flight of stairs, which had a hallway running along side it. As he was walking back down the stairs, he didn't see the other framer walking the same direction down the hallway. Dave, the upstairs framer, hit Tommy, the other guy, in the head with his nailgun, planting a 10 penny nail right in his skull. Miraculously, the nail failed to come into contact with Tommy's brain (a fact for which he later paid dearly in the insult department). Funny thing is, Tommy wanted someone to pull the nail out with a pair of pliers because he couldn't afford the time off of work. They forced him to go to the hospital, but had to offer to keep him on the clock while he was there.