In the depths of the Internet, secret groups of mega-fans cluster around story franchises and write about them. Their work, containing the same characters and often setting of the original work, is known as fan-fiction. Once upon a time, Cassandra Clare was a "Harry Potter" fan-fiction author.
Clare, like E.L. James (another former fan-fiction author) has risen from the insular ranks of the Internet mega-fans with her bestselling "Mortal Instruments" series.
But now, since Clare's success, blog posts filled with vitriol abound, alleging that she got kicked off of a popular "Harry Potter" fan-fiction website for plagiarism in her fan-fiction. There are multiple Tumblr accounts dedicated to these accusations. A small group of angry fans continue to accuse her of plagiarism and cyber-bullying in the comments section of nearly every site writing about her. (Good thing we disabled ours.)