Busybodies

It would probably be safe to say that more than half of the evil in the world is due to well-meaning busybodies who just cannot refrain from interfering.  Needless to say, such people never have harmony or success in their own lives, for it is an invariable rule that he who minds his neighbors business, neglects his own.
-- Emmet Fox 

(Note, though several of Fox's quirky ideas are off base, this one rings true.)