Before Cassandra Clare became a published author, she was involved in a lot of controversy in the Harry Potter fandom. Some of Clare’s online misdeeds include cyberbullying and cyberstalking.
She also has plagiarized parts of her famous Harry Potter fanfiction trilogy (The Draco Trilogy) and shut down an anti-Clare blog claiming that they were anti-Semitic bullies.
The Shadowhunter Chronicles has shoddy worldbuilding and an incest fetish, along with being biphobic. Also, there is also a lot of m/m fetishizing.
The Shadowhunter Chronicles
City of Bones: A Mary Sue falls in love with a handsome douchebag and discovers that all mythical things are real. Just like any another YA urban fantasy novel.