I've 2 questions
a) can anyone look at my tweets? What about people who haven't actually signed up to follow me? Would I know they've looked at my tweets in this instance?
b) When someone's facebk/twitter a/c says things liked 'x has just checked in here', have they actively done something with their mobile at that point in time to tell FourSquare where they are.. or does it just do it automatically once you've generally signed up to FourSquare?