That's why that chain is on the hand truck, dumbass. Chain it up and you won't get a mouthful of compressed gas tank.
That reminded me of a story a former co-worker told me years ago. He was working on a rig off the Louisiana coast, and oxygen and acetylene tanks stared disappearing. No one could figure out why until late one night a guy just happened to be looking the right way to see something shoot off the side of the rig into the darkness. He told his supervisor what he saw and they went to investigate. They found out that a guy had welded two pipes to a rail, pointed out away from the rig, in such a way that he could push a tank up onto the pipes. He would put a tank on this makeshift launcher, with the bottom of the tank pointed out to sea, and knock the valve off the tank with a hammer. The tank would then take off, like in the video above. This greatly entertained the knucklehead, until he was caught. A boat brought some more tanks the next day, and the knucklehead got to ride back on the boat to where the appropriate parish sheriff arrested him for criminal mischief. I guess it was fun while it lasted.