There have been some incidents of crazy fans at cons, shouting at creators for "stealing their ideas." Way back in the early 90s, Comic Buyer's Guide published Harlan Ellison's "Xenogenesis", which detailed lunacies and attacks by sci-fi "fans" against himself and others (someone threw a cup of warm vomit on Alan Dean Foster). There were remarks of similar things at comic conventions. Anything that draws that level of zeal is going to see the excesses of it. It seems more of it has popped up online, thanks to social media, and less in person, as that requires confrontation; something the disgruntled often avoid.

Funny thing, Robert Rodi put an element of this into his novel, What they Did to Princess Paragon. The book deals with a hotshot comic creator from the "big company," that is hired by the "classic company" to revamp their old character Princess Paragon, a Wonder Woman analogue. He is a closeted gay man and decides to push forward the idea of her being a lesbian (something that always dogged Wonder Woman). The desperate publisher thinks it will draw attention and runs with it, hiring a lesbian editor from the indie world to oversee the book. A repressed fan, who works as a night security guard, at a grocery store, hears about the changes and decides, for the first time in his life, to go to a convention, to confront the creator. They meet in a stairwell, when the creator bolts from a panel, after getting a ton of negative comments from the audience. An accident ensues and he is hurt and taken to the fan's home for care and treatment. Really good book, long out of print. Rodi was a longtime letter hack and fan writer (including The Comics Journal) who wrote several novels, most with gay themes. He also wrote the comic series Codename: Knockout, and several other comics.