In 1990, long before there were trolls to haunt your mentions or poison Facebook comment threads, there was Usenet, a sort of proto-Reddit that predicted much of the promise of the social web — and, as regular user Mike Godwin observed, many of the pitfalls of networked interaction. "The Nazi-comparison meme," he recalled of Usenet's early days in a 1994 essay for Wired, "had gotten out of hand." Inside Usenet's discussion groups, he wrote, "the labeling of posters or their ideas as 'similar to the Nazis' or 'Hitler-like' was a recurrent and often predictable event." To Godwin, who came to be deeply moved by the plight of Jews during World War II, casual comparisons to Nazis were thoughtless and reckless, dangerous language that served to immediately halt debate, not to mention liken any difference of opinion to an episode of monumental human suffering. "I wanted folks who glibly compared someone else to Hitler or to Nazis to think a bit harder about the Holocaust," he later wrote.

The phenomenon Godwin observed in that essay quickly became crystallized as an internet truth, now known as Godwin's Law: The longer an online discussion grows, the more likely it is that a comparison to Nazis will be made, thereby derailing and ending online discussions. At more than two decades old, Godwin's Law has been a trope almost as long as the modern web has existed. But is it true? Do all web conversations inevitably descend into historically shallow Nazi analogies?

That's a difficult question to answer, one that would require a massive dataset of web comments, spanning a variety of subjects over time. It's a good thing, then, that a redditor named "u/stuck_in_the_matrix" downloaded every comment on Reddit (it only took 10 months!) and offered to the world a compressed mass of internet ephemera.

Another redditor, with a penchant for data science, and the strange ability to count statistical learning models as a leisure activity, saw in the comment dump a towering heap of hidden treasures. Travis Hoppe, a Ph.D. in physics, grabbed the data stockpile and put Godwin's Law to the test.

"The really important part about this whole study of Godwin's Law is it's not a study of finding Nazis or Hitler on the internet," Hoppe told BuzzFeed News. "And it's not a study to make light of the atrocities of WWII and the genocides. It's really a study about how we treat each other on the internet."

Hoppe analyzed every one of the more than 100 million posts on Reddit — and then he examined the 1 billion comments those posts generated. He found that out of all the submissions, nearly 200,000 invoked Nazis, Hitler, or some variation ("feminazi", "obamaisliterallyhitler," islamonazi") at least once.

That's a staggering amount of Hitlers and Nazis in various forms, but it's still a relatively low frequency — 1 out of every 1,500 submissions — which Hoppe believes discredits Godwin's Law. But a few other findings surprised him: Hoppe found that comments on a Reddit post typically peak within hours of an item's submission, regardless of whether or not they fall victim to Godwin's Law, and that Nazi references often crop up early in the commenting lifespan of a post. "What this means is that conversations keep going," he said. If playing the "Hitler card" in an online conversation really does effectively end it, as Godwn's law assumes, Hoppe's analysis should have shown that Reddit's Nazi references come toward the end of a thread. Instead, he found the opposite.

Either redditors are learning to ignore offensive, Hitler-mentioning trolls, "or, here's the super interesting hypothesis," Hoppe said: Nazi references aren't just a given — they're a measure of how controversial a topic is, suggesting it's something people want to discuss. "There seems to be a correlation between the Hitler-trolls, if you will," Hoppe said, "and something that's interesting to talk about." Hoppe made clear that this theory is unsubstantiated, but he said it seems to be supported by the data. Another explanation, considering Reddit's white power contingent, is that conversations continue but are colored by hateful speech. Hoppe anticipated this point. But he isn't sure how to create a reliable, automated way to classify bigoted language without depending on humans to flag content. It's not clear if Facebook or Twitter know how to do that either.

This kind of project — studying enormous amounts of information spit out by web platforms — is an engrossing hobby for Hoppe. He presented his Godwin test at this month's Hack and Tell, a Meetup event in Washington, D.C. where hackers show off their cleverly manipulated datasets in a sort of Homebrew Computer Club for dataphiles. Earlier this year, in a novel take on machine learning, Hoppe created a bot that successfully generated dozens of popular posts for a subreddit called Today I Learned. His algorithm was shockingly good at earning upvotes. And nobody but him knew it was a machine — a Turing Test for robot news-writers.

To improve on his latest experiment, Hoppe is eyeing platforms beyond Reddit, ones with more diverse demographics. (As far as Godwin's Law is concerned, is Reddit pathological or representative of the broader web?) Another question Hoppe is considering: Even if conversations continue after a Godwin's Law invocation, is the content or the tone altered for the worse? And do these types of mentions concentrate around specific topics — say, politics? Hoppe said a glance at the content had Godwin-type analogies frequently attached to Presidents Barack Obama and George W. Bush. But it may be that these mentions are distributed across noncontroversial topics too. (Hoppe wonders how long it takes for other keywords to show up, like "Jesus" or "puppies.")

In the meantime, though, Hoppe's understanding of forums like Reddit has deepened. "Much of the the good stuff on the internet is conversations — be it words, art, code," he said. Godwin's Law may not turn out to be airtight as the kind of scientific laws it's wryly named for, but it illuminates something real about the trials of talking online, and the ease with which conversations can turn sour. At a moment when many online communities (most notably Reddit) struggle to negotiate relationships with their less-than-savory users, the connection between vigorous debate and virulent hatred is as important to consider as ever. "Even if Godwin's Law is not true," Hoppe said, "it causes us to think about the times it is true."