To clarify some of the issues raised in this thread:
This work is part of a larger project that is funded through the EPSRC with support from the DHS. However, all of our work sits in the public domain and we work within very clear and thorough ethical guidelines which deal very explicitly with issues of confidentiality, data protection, and data sharing. For every individual, data will not be viewed by anyone other than those directly involved in this research. This means that our funders do not see an individual’s data, only the overall results of our research. The first thing we send to poterntial participants is an information sheet which provides full details on what data we are collecting and what we are going to do with those data, so anyone participating in the research receives full information before anything else actually happens. We are very happy to provide reassurance on this both through this post and through individual communications if preferred.
In terms of the research question of this specific study, we are primarily interested in what factors go into people's choices of avatar. What is it that makes one person chose one type of avatar and a different person chose a different type? Why do some people chose to use avatars that reflect their RL appearance, whilst others do not?
Finally, you're right that by looking at second life we are to an extent pre-selecting the sample, but we've chosen Second Life because of the freedom people have in editting their avatars.