|No such thing as a small change
I have heard this sentiment before, many times. While true, it doesn't express the whole truth.
Sure, people who would ordinarily be polite often turn abusive online. But people who would ordinarily be shy open up. People who are tongue tied wax eloquent. People who can be browbeaten become steadfast. And if your were getting by on good looks and charm before, well, online might be a problem for you.
Why do these transformations occur? Who knows, but it is nothing new. Have you ever read a letter to the editor? Or noticed the difference between your phone conversations and your real ones? How about when you are talk to a friend on an elevator, and a stranger steps in?
Humans use different modes of communication in different situations, and the Internet new and different and evolving.
Different != Worse