If there's one thing humanity is disturbingly good at, it's killing its own. We have an unparalleled ability to destroy ourselves and everyone around us, via war, famine, and the occasional attempt at collectivization. These 14 examples show just how adept we've become at self-slaughter over the past 2000 years, and are the most deadly punishments we've inflicted on ourselves.
No one's going to argue that Josef Stalin was a vicious murderer of millions, but I never realised how bad his policies were. In the early 1930s, the forced collectivization of farms in the Soviet bread basket lead to unmitigated chaos. Farm machinery was destroyed, and no one had any idea how to efficiently maintain a farming network on a collective scale large enough to feed the millions of citizens in the USSR. All the grain that was produced was shipped off to Moscow, and farmers were forbidden from eating what they had grown. This lead to the death of anywhere from 2.5-10 million, especially in the Ukraine, where it was known as Holodomor, the 'hungry mass-death'. Now recognised as an act of genocide, it was originally kept out of the history books for being anti-Soviet, so the true estimates of the effects are hard to judge.