Colin Walker makes a statement I personally profoundly disagree with when discussing social networks
With the best will in the world, and despite our best efforts to be authentic, we all play a roll online - just as we have to offline depending upon the circumstances we find ourselves in.
I do not play a roll online or offline. I am myself in both places. I may think more before I post online (sometimes) than I do when I speak to someone in person offline. But, I do not play a roll.
Of course, that's not to say people don't play rolls in life. It just says that I find it tiring and do not engage in that behavior.