This may lead to embarassment when you realize you've been up to the elbows in poo and are now covered in it.
It may get even worse when you discover later it was not even the right poo, and in fact you were just being horrible to someone while telling yourself you were doing acts all in the name of What Is Good And Right. The object of your education campaign may not be happy about your methods even if your heart really was in the right place. Vicious means never justify even the most noble of ends - eventually it becomes about the means and nothing else.
That said, it's odd how rare the talent of calling someone's shit in an effective manner truly is.