XBox Live and Privacy

XBox Live’s default settings allow others to see what you’re doing.

Simply put, anyone you’ve been in contact with through Xbox LIVE can subsequently see what you’re up to, regardless of whether they’re in your friends list or not. […] The amount of detail Xbox LIVE passes to others goes way beyond just being helpful in linking you up with other gamers, so far beyond that you could easily regard it as a pretty major intrusion into your privacy.

Via eHomeUpgrade and HEXUS