Dean is harmless. He wouldn't hurt a fly unless you pointed him at it and said it was food.
Everyone's powers are going a bit haywire, and instead of inciting pitchforks and torches, how about you surmise that there's something wrong with whatever power you have. Or, I don't know keep your fucking mouth shut.
And even if he is undead, do you think he's the only one!? There's nothing that can be done about it even if he is! As far as I'm concerned he is 'less blue' and that's it.