Question, when he calls and hangs up does his magic jack stuff internet trace your ip?
Is that what he's doing?
When user X calls user Y on Steam, X opens a direct connection with Y, sends some authorization so that Y knows the user's Steam ID, and then the Steam interface changes to reflect that call and adds controls (when you accept it just streams audio directly through it). Since user X connects directly though, Steam has to send them the IP of user Y to connect to first. While you're in a call then you can just check any kind of "active connections monitor" for the IPs that Steam's child processes are connected to.
