What is it that makes people so mean on the internet?

[NuclearEnergy]

I have been called some incredibly hurtful things on the web. Mostly on Facebook. Probably because when you engage someone in a debate attempting to use logic they do this thing where they sift through your Facebook profile to find a "flaw" in you because they have no other arguments. This is one of the reasons I don't engage people anymore on Facebook. No matter how idiotic of a statement they have made. 

For instance, today I made statement that angered those raging patriots on Facebook. And boy, the nastiness sure comes out. It was like a shark feeding frenzy.