You know that you have a Mary Sue when she upsets the monochromatic color scheme of my Writer's Guides.
Mouse over blue text to see a note.
Internet communities often lash out at writers who create Mary Sues. Declaring the writing to be below their standards, they proceed to punish the creators. They mock the characters, verbally abuse the writers, and write hyperbolically about how much they wish the characters would die.
Bullying writers (who may be very young) is only going to make them afraid to write—and therefore improve—or share their work. Not only that, but it discourages other writers from speaking for fear of public mockery, and it may silence the voices that could someday become great.
If you've directly or indirectly suffered from the abuse of such individuals, let me first apologize on their behalf. I don't care if your story stinks so much that it can be smelled from fifty miles away; mocking you