LW has a few role-playing characters identifiable by usernames, while others don't appear to be playing such games and don't use speaking usernames. So "Voldemort" is likely a fictional persona tailored to the name, rather than a handle chosen to describe a real person's character.
Who are the other role-playing characters on LessWrong?
From Mike Darwn's Chronopause, an essay titled "Would You Like Another Plate of This?", discussing people's attitudes to life:
Conclusion, graphs, and references in article. As usual, I recommend reading Chronopause.com as Darwin has many good articles; to quickly link a few: