Xbox live doesnt have a very secure database. They're financial end is sub contracted by microsoft and is very secure but the actual user database with names address' and emails is fairly open. It's just not something I would do. It was brought to my attention when I was trying to find people on here t play Nazi Zombies with. Someone PMed me saying the same thing so I asked my father who does internet security for a living. He managed to lookup all my information from Sonys database and told me xbox was the same system or at least very similar. Better safe than sorry. It's scary what these computer wizzzz's can do. The new software they're developing now can fish out your actual address through up to 4 proxies. It's pretty crazy.