Recently one of my players disclosed that I, as DM, have the power to destroy the party of characters at my whim. His words taken from the conversation were, "...send in a few more dragons,'Cuz that's the kind of power you wield."
I guess he's right. I could arbitrarily destroy the party. Every week, the moment after my players make new characters... Their dead.
I suggest that I don't really have that power. It's like having power to nuke the entire world. Then what? If you want to have a game, then you can't use that power. If you want to keep your players, and want to have a growing, positive experience, then start with respect. Their characters are an artistic expression. Let them pursue their stories. I digress.
Some people (I won't call them players) enjoy having their characters killed by their crap DM in clever new ways. That's not playing. That's idolizing a clever bastard. Do what you want to do, but I hope someday you will respect yourselves and each other better than that.