Famed computer programmer and businessman John McAfee took to Twitter to show off what he claims to be a fully automatic pistol that runs on "massively compressed hydrogen" and no gunpowder. 

He captioned a video of him shooting the gun, which he says costs $180, "A friend showed me this weapon on a Web page.. Supposedly legal in all 50 States. Can fly commercial with it without declaring. Supposedly. Fully auto. $180. Asked Karl how it works. He claims cartridges contain massively compressed hydrogen. No gunpowder? I think I'll hide it." 

He then added, "Disbelievers about the legality of carrying the previous post's gun on an airplane: i have fancy guarantee, in broken English, from the company. And . . they sent a letter, in Polish, signed in blue ink, instructing Homeland Security not to interfere. So the last laugh's on you."