Coffman will recall that she feels “totally disoriented.” She cannot believe that an innovator in mass murder would have tried to protect the Jews and other supposed subhumans his troops rounded up. She checks the footnotes. The claim is attributed to War of Extermination, a compendium of academic essays originally published in 1995.

Coffman knows the book is legit, because she happens to have a copy on loan from the library. When she goes to the cited page, she finds a paragraph that appears to confirm all the Wikipedia article’s wild claims. But then she reads the first sentence of the next paragraph: “This is, of course, nonsense.”

The level of bad faith is eye-opening for Coffman. She is “very appalled.” She sees that her confidence in Wikipedia was “very much misplaced.” All it takes to warp historical memory, she realizes, is something this small, achievable for almost anyone with a keyboard. “So few people can have so much impact, it’s a little scary,” she says. She begins to turn a more critical eye to what she sees on Wikipedia. Especially the footnotes.