I've been interested to read about Facebook's plans to offer "location based services". Like so many other online experiences today (especially embedded advertising), this is part of the meta-trend to customise one's experience of the Internet based upon end-user geo-location.
Wow that's a lot of jargon. Let me try again.
This is another side of how the Internet now "works": what you see on "the" web depends on a combination of what you put into your browser plus where you are physically when you do it. Your physical location has become a significant factor in determining what you see.
So while I am certain that Facebook's roll-out of location based services is being done for the best of business reasons, they are creating one more piece of the infrastructure that will enable better enforcement of sovereign borders upon the Internet.
Think of it like this: now that Facebook will "map" the geo-location of its end-users, how long before the sovereign government of Ruritania issues an order to Facebook to "block" the content of certain FB pages to all persons who are geo-located in Ruritania?
Now that we know the Internet has borders, the race is on to develop technologies that will assist in enforcing them.