Fan Fic - Yes or No?

So I know there's always this raging debate about fan fic. Is writing your own stories about characters you love a means to creative expression or stealing from the author?

I know of several teens who write Boys that Bite based fan-fic and have published it on the Internet. And while I feel this should bother me in some way, actually I feel just the opposite. I love that my book inspired kids to write their own stories and express themselves on the page. (Or screen, as it were.)

Here's one example of a budding young author's Boys that Bite inspired story.

What about you guys? Would you be flattered or dismayed if your characters starred in Internet fan fic?

Mari