I was having a discussion with someone the other day (Talyna, I think) about being someone you're not in SL. About being a different person. I, in my noob naivety, suggested that it would be possible to be someone completely different to SL. To live out a life detached from RL. Do things you would never do in RL.
Her battle-hardened counter-argument was that you cannot hide the real you. You might put on a different face or a different body, a different sex or a different race, but ultimately an arse is always an arse.
I suggested she's meeting the wrong sort of people as a pole-dancer.