Like all of God's children, prescriptivists can be assholes. Generally the worst offenders are also the worst-informed, but even they should know better than to correct someone's grammar in casual conversation or use [sic] for the purposes of evil. All the book-learnin' and mock-outrage in the world doesn't exempt you from common courtesy.
Today's prescriptivist asshole comes to us from Best Pic Ever:
Hey, do you want to be happy? Then stop being a dick. It really does work.