Comment by joakin

If googles philosophy is data openess they wont close their API, but instead they can warn their users about something that non of them knows.

As for what you say is the question under discussion, as somebody said over here, facebook can perfectly distinguish between a user exporting his contacts and an app trying to scrap personal info. They wont do it because they dont want anybody to export his relationships (in email adresses terms) so that they can rebuild their social graph out of their webpage. Facebooks leverage is users, and that action would make possible for users to migrate.

In any case, facebooks behaviour only damages users ability to control their data (or at least have a backup of it)