[WingsToDiscovery]

Someone once wrote:
The reality of the internet: "Where men are men, women are men, and children are cops."

On a serious note, you answered your own inquiry. Anonymity on the web gives us the power to say or do things we would not normally say or do on the internet. This could include saying things that are hateful often without direct reprocussion.
This can also explain sex identity. I've known female video gamers who choose male avatars to avoid harassment from male counterparts who would normally not be so rude. I've met male video gamers who choose to use female avatars as they like to dupe dumb users. These are just two examples of how people can use anonymity to be whoever they want to be. And that's exactly why they do it.