One of the things I love writing about urban fantasy is there aren't many rules. Happy endings aren't required, violence is expected, and sex is encouraged. Basically, the loyal readership isn't easily shocked, which leaves a lot of room for us writers to let our deranged imaginations play.
For example, here at the League, we have authors writing about zombies snacking on appendages, gratuitous demon sexoring, graphic descriptions of blood-letting, characters killing without remorse, and any number of other things that might get us kicked out of polite cocktail parties if we brought them up. Which is why we aren't invited to many polite cocktail parties--or parties in general.
But what do you think? Are there sacred cows in urban fantasy? Aside from the normal taboos--harming children, for example--is there any subject that would turn you off of an author's books?
*Edited for wonky html issues.