Yes, I think that anonymity makes cyber socialization less authentic, because people say and do things on the internet that they would not do if they knew that the people with them knew who they were. Anonymity lets down people's defenses, and it also makes them more mean to each other.
I do think that anonymity makes cyber socialization less authentic. The problem is that people either pretend to be something they aren't, or they are much more open about every aspect of their lives than then would normally be. There's either fraud or no filter. Both of which aren't matched in the real world.
I haven't heard the word "cyber" used non-ironically since about 1996. Anyway, anonymity isn't the problem. It's people that don't configure their social networking apps to reject interaction with people they don't know that causes issues. If you leave yourself open to interaction with strangers, you're going to run into some inauthentic people.
When a person chats with someone online, they are most often anonymous. When a person is anonymous through an online web service such as ChatRoulette or Omegle, he or she is often very different than in person. Socializing on the internet is never a good idea because it takes away from real socializing in person. Socializing needs to include eye contact and body language, which cannot be possible on the Internet.
Anonymity is important. It creates outlets for people to have conversations about controversial or taboo subjects. It has the potential to open people's minds. A great number of conversations are pointless, but sometimes people use anonymity to talk about controversial subjects and that's important. People can talk about issues they normally don't get to talk about.
Another thing anonymity makes easier is whistle-blowing. A person can expose wrongdoing in an organization they work for without risking getting fired.
And we even benefit from the idiots using anonymity. For example, Fundies Say the Darndest Things has posts on there from the most ridiculous fundamentalists. By being willing to go over-the-top homophobes, racists, and religious zealots discredit themselves a lot more effectively than if they weren't anonymous and so were being more careful about what they said online. People probably wouldn't be so supportive of gay rights today because anti-gay people would've been carefully about not posting things that sound too outrageous.