Yes, it is important for a person to be his/her self online and not try to be deceptive. Being sensitive is very important to protect the feelings of other people. The possibility of building friendships is wonderful. When a person is feeling badly, sadly, or depressed, they often need someone to lift them up, and a little cheer from a friend really helps. I like to give that, and also there might be a time when I may need that myself.
There is a scripture that says "be sure your sin will find you out." It might be fun for some people to be deceptive online, but eventually the pay day comes, when the truth comes out, and there is reality for the deceptive one, and often times hurt for the innocent ones. My opinion is that everyone should be for real online, but I know that not everone practices that. This is like the idea that it is less complicated to be honest, because you don't have to cover your tracks, and tell more lies to cover the lies that you already told. It is much better all the way around to be honest!