The humble beginnings of “Fifty Shades of Grey” are the stuff of legend. E.L. James, under the pen name Snowqueens Icedragon, began posting erotic stories using the characters from “Twilight” on fanfiction.net.

Droves of users gobbled up the racy stories, and James leveraged her popularity into e-books, which in turn garnered her enough buzz to get an actual book deal. The “Fifty Shades” trilogy has now sold more than 100 million copies.

But many in the fanficton.net community are confused and concerned by James’ success. “The prose style, the dialogue — it was very juvenile. It was very simplistic,” says Karen, a 50-year-old administrator from Phoenix who uses the name piewacket on the site and recalls reading James’ original posts.

Fanfiction.net is now scraped of James’ early writing, but the site is alive and well — at least for the time being. Many worry that James has put the entire community at risk by profiting from fan fiction.

“The concern is that once people start making money from it, the authors or the publishing houses might turn around…and say, ‘Uh uh, no more. Copyright infringement,’ ” explains Karen.

“I personally don’t think fan fiction authors should pursue publication,” says Laurie, a 25-year-old literature grad student from South Carolina who uses the pen name Ever Searching. “It’s more about integrity than money.”

And there’s worry that the graphic sexual content in “Fifty Shades” reflects poorly on fan- fiction writers.

“Of course the one area [of the community] that rises to big public attention is pornographic,” sighs Karen. “Now people think we’re all a bunch of — to use the term people always use — ‘bored lonely housewives’ or just ‘women writing mommy porn.’ ”

Tom, a 22-year-old warehouse worker from the Southeast who uses the pen name militaryhistory and writes “Lord of the Rings” fan fiction, found the book’s abusive relationship disturbing and the understanding of BDSM misguided.

“The whole thing honestly reads like masturbation material,” he says, “as opposed to an actual story.”