Really, it's a matter of what you make available. I can't imagine "stalking" somebody ever really being a good use of time. What bad things are there to find? Drunken pictures? And that's on Facebook, behind a wall.
It's always fun finding 10-year-old, embarrassing news articles or pictures of someone. :) Also, if you're one of the many people who use MySpace instead of Facebook, those drunken pictures aren't behind a wall.
Really, it's a matter of what you make available. I can't imagine "stalking" somebody ever really being a good use of time. What bad things are there to find? Drunken pictures? And that's on Facebook, behind a wall.