As the eagles song Hotel California says - "You can checkout any time you like,But you can never leave!" Like so many services - proprietary services - like Google, yahoo, Facebook, etc. - they want us in but we can't get out - unless they say so - and they keep our luggage ! And they can, arbitrarily, as discovered by Robert Scoble - lock us out and just delete our account and data.
This should be a flag for all those educators espousing the use of third party social networks like Facebook in education. Alternatives, like Elgg, allow universities or educational foundations to run their own social networks, and not be prey to the whims of proprietary systems. As Robert also discovered the open ownership of our data and the portability thereof should be of prime concern! We are visitors to these sites, not seeking to become an inhabitant that is treated like a chattel. We own our ID and must be able to port our data whenever and wherever we want - see these principles espoused by the dataportability movement.
As Stephen Downes cites Steve O'hear " "the resistance of Facebook, MySpace, Google and most of the leading players in the user data space to offer easy data portability (I can't even backup my gmail with a simple one-click) is based on an old fashioned notion that lock-in is the best way to protect a strong market position." The whole promise of social software and open source was NOT to be locked in - that's why many of us in ed tech find the proprietary Learning Managment System as so much less than the grazing commons of the personal learning environment (PLE).
As a side note I am on Facebook and am also involved in an effort to search out our family roots. I found others on Facebook with the same surname and was sending them a message of introduction and inviting them to our surname site. The Facebook robots warned me that I was "spamming" and shoud desist. So much for a social site.