One lie I find annoying in modern fantasies is when fictional worlds are forced into our reality by making the monsters and magic a total secret from the rest of the world. I guess I can understand the desire to bring vampires and fae and whatever into our world, but it is fiction after all. Why do these modern fantasies need to have anything to do with our world?
Some authors (Laurell K. Hamilton) write about worlds like ours, but not--where monsters are real and everyone knows about them, if not the details. These worlds skip the unnecessary lies--the ones which rely on fictional secrets to keep the masses from panicking. Now the unnecessary lies are sneaking into TV and movies. Maybe they were already there. Maybe I'm the only one in the world who finds this annoying.
On the other hand, if I ever write a book about vampires and werewolves and whatnot, I might throw in some quantum theory and a bit of magical thinking (is there a difference?). Everyone in my modern fantasy would create and live in his or her own universe, and they would overlap where the reality perceived by each person matched. No one would notice the differences unless they had training.