The Fangirl

I wonder how many people realize that Jace (aka Draco) is basically Spike from Buffy the Vampire Slayer. I mean, she even used Spike's dialogue for Draco in the Draco Trilogy.

What I mean is that when she wrote the Harry Potter fanfic The Draco Trilogy, she merged Draco Malfoy with the Spike character to create her version of Draco. That same character was given a new name, Jace, and turned into a Shadow Hunter, instead of a wizard, for her Mortal Instruments series. Yet the traces of the characters are still there. Especially the similarities to Spike.

Physical Description

"[Jace] is described as having fine, curly, golden blond hair and eyes that look gold in the light with long eyelashes. He has a slim, muscular build and is about 5'11" in height. His face is often described as being beautiful, sexy, gorgeous and angular and Clary often refers to him as beautiful and leonine, with a narrow mouth." [source]

Clare even used actor James Marsters', who played Spike, chipped tooth (that was a the delight of many of his fangirls) in the formation of Jace's physical apperance. "The only flaw in [Jace's] face, as Clary has noticed, is the slight chip in his incisor teeth."

Personality

"Jace gives the impression of holding most people in disdain but is quite chivalrous toward women. He is extremely arrogant, [...] He can also be very sarcastic [...] very confident about his looks and has dated a lot of girls, [...] His charisma, good looks, and charm have made him quite the ladies' man, and he is implied to be somewhat promiscuous among girls." [source]

You can see in comparing dialogue how Clare "rewrites" other people's work to adapt it to her own books, and how poorly she does it. 

Spike: "I know you'll never love me. I know that I'm a monster, but you treat me like a man, and that's..."

Jace: "So I see who I am in your eyes, and I try to be that person, because you have faith in that person and I think faith might be enough to make me what you want."

Clare is hardly the first writer to do this. I recently read a blog post (which I will link once I find it again) about how a lot of the popular Motorcycle Club erotica are complete rip-offs of the FX series Sons of Anarchy. Not only copying characters, and plot points, but even dialogue. 

Then there's the case of the book the m/m romance novel Bear, Otter and the Kid which borrows heavily from the film Shelter. It stirred up such a controversy the publisher of the book, Dreamspinner, had to put out a press release insisting it wasn't plagiarism. 

Where do we draw the line? How do we know when a character or story for that matter is "inspired" by another work or an outright copy? Do you even care if an author borrows heavily from other mediums like tv or movies to create their books?

How far is too far? 

Is the situation with Clare's Jace similar to Joss Whedon admitting Mal from Firefly is based on Han Solo? 

What do you think?