There, I said it, just in case someone comes up with a dare for me, thinking I won't bad mouth a lot of stuff because his local clergy brainwashed him into thinking the Cold War is still going on and anyone who disagrees with him is a Rusky.
Stalin was a villain for sending people to gulags and to executions for political "crimes" like exercising free speech in favor of evolution and heredity. Stalin operated in the same manner as a theocrat, declaring this or that theory as "a bourgeois pseudoscience" for not supporting The Party. Sorry, but government officials are no more entitled to their own facts and evidence than churches are. Stalin was evil in many ways, but he was evil for the same reason the directors of Inquisitions were evil.
Lots of Communist leaders engaged in mass purges, also a very big evil that I will never condone. I'm sure all my atheist friends here will agree that such things are evil. Mass killing is also bad if done in the name of some insane racial ideology, not just because it's mass killing, but also because it makes the human gene pool even shallower than it already is. It also involves a great deal of hubris to think that we have the ability to determine superiority, since that would require calculating a dizzying number of factors. That's why Hitler was unambiguously evil, too. And stupid on the biology front, to boot.
What a lot of this boils down to is that I think the various fascist and communist tyrants are evil are for the same reason I think violent fundies of all stripes (that includes those who threaten people with invisible violence in Hell) are evil. They're the same thing with a few cosmetic changes.
The only "persecution" I'm going to do involves making fun of people in ways that typically expose their fallacious thought. Everyone agrees with me, right?