Is religion dumb and dangerous?

I'll save dumb for later, aside from observing that today's active atheists often seem to be interested in reaping the gloating and other perquisites of being a freethinker, without all that tedious mucking about in actual thought, instead quoting catch phrases like so much duckspeak.

Maybe more people have been killed for religion than for anything atheistic; after all, atheism didn't gain ascendency until the 20th century, whereas people have fought over religion--but also other things perpendicular to religion, like territory or other resources--for millennia before then. Well, howsabout we tally up the deaths under regimes and philosophies that are post- or anti-religious, or anti-Christian, at least?

I'm not trying to make excuses for or take attention away from the things nominally God-fearing people have done wrong. Most of the crusades after the first were ill-executed, if not ill-conceived. We sin doubly when we claim there exists and we abide by an objective and absolute moral standard, and fail to hold ourselves to it. The fact that I'm mostly picking on communist/fascist historical events is also not meant as a relativistic exoneration of injustices enabled under capitalism; capitalism isn't theistic or atheistic, but in proportion to how Marxist they are (theism under economic communism being hypothetically possible as well), socialist or fascist systems are specifically atheistic or otherwise opposed to organized religion (organized government by definition not deigning to suffer competition for institutional loyalty).

Most of these deaths are executions. Many, however, are from starvation and neglect, such as Mao's five year plans failing to take reality, in the form of lack of industrial expertise and infrastructure and noncompliant weather for farming, into account; or Stalin shipping off trainloads of actual or potential troublemakers to Siberia where they could hardly sustain themselves. While not all the non-execution deaths were malicious, they still indicate a failure of a post-theistic system to be of any benefit to large numbers of people. Some sources put Stalin's and Mao's death tolls at twice the upper limits I have listed.

Papa Doc: 30-60k. Small potatoes--I include only because even the lower range outstrips the total deaths under the Inquisition, even the harsh--and meticulously documented, if you'd care to see for yourself--Spanish Inquisition.

Pol Pot: ≤ three million
Sukarno: half a million, not counting ethnic Chinese in Indonesia (this regime was somewhat theistic, but otherwise was pretty faithfully Marxist)
Khmer Rouge: 1.5-3 million
Mao's cultural revolution: 30 million
Stalin: 10-30 million
Hitler: Hitler was fascist, but anti-communist, and he was no Christian, despite any early political rhetoric that might still be on record (claiming there was no bull of excommunication shows you don't understand how the Congregation for the Doctrine of the Faith works); in addition to the six million Jews that were killed, three million Christians in Poland alone were also slaughtered, with Christians elsewhere and members of other suspect groups adding up to another million or two. Let's say 10 million--it's nice and round.

See Mass deaths and atrocities of the twentieth century at Wikipedia for more details. You can look up the data somewhere else if you don't trust the numbers there; they cite plenty of other resources for you to compare, so it's at least a worthwhile starting point even for Wiki snobs.

What's our total? 55-76.5 million, just counting the top six causes (that I could think of) during the twentieth century--not even taking up the whole century. That death toll is as many as the black plague worldwide in the middle ages. Do you still want to argue that the Crusades--a million or so over the course of two full centuries--can hold a candle to these figures? Even adding in deaths at the hands of the Saracens (religious in their own right) during the same time period, it's just a drop in the bucket.

Have there been more religious deaths all throughout history than atheistic ones? Maybe so, but the irreligious sure made up for lost time in the 20th century. Sure, we also have more people nowadays, so the proportions are different, and most religions are more laid back than they were a thousand years ago, but these caveats don't exonerate the modern era's mass murders.

The world population--never mind Europe--during the middle ages was around a quarter billion. It grew over the centuries, but a quarter billion's a convenient average. The Crusades and the Inquisition don't account for two million people, 0.8% of the total population, over a few centuries.

In the first half of the 20th century, it was around two billion people. Contra-religious deaths are as low at 55 million, as high as 100 million if you include abortion, but let's stick with 55 million: 2.75% of the world population, over a few decades. Making up for lost time, indeed.

Never mind that in our enlightened modern era, we're all supposed to be above such horrors as genocide, but apparently only the Church learned anything from the scandals of the Crusades.

"Freethought" indeed. I know of a respectable number of theological skeptics who aren't afraid to cogitate on the hard questions, but most of the time the only response to "What about Mao and Stalin?" is "Uh, Hitler had to be a Catholic in good standing, and besides, their governments weren't atheistic; they were just political entities rather than religious," as if being expressly anti-theistic was really no different from mere silence on the issue.
More like "Thought-free."