What is it About Email and the Internet That Brings out the Worst in People?

Have you ever noticed that people seem to be more willing to say anything through an email and on the internet than they ever would in person? I belong to a number of email listserves and every once in a while someone will take something the wrong way and respond in the most vile nasty way. What's up with that? And I imagine these people wouldn't dare to say anything like that in person.

Do they think before they speak? Or is it because no one is standing in front of them they feel like they can say anything they want? What happened to manners? Or if you have a problem with something someone said how about you contact that person? Instead of emailing the entire email list that sometimes consists of hundreds or thousands of people? What is it about the internet that makes peoples manners just go into the toilet?

Or are manners in general just going bye bye? There are so many more instances of road rage than there ever used to be. And you hear stories about people attacking people with 13 items in the 12 items or less checkout line? Why are people so angry?