At day two of the Web 2.0 Summit John Battelle and Tim O’Reilly asked Mark Zuckerberg why Facebook pulled its social data from Ping:
He says that Facebook has had to invest tens of millions of dollars into infrastructure to enable games from large developers like Zynga, which is why Facebook and Zynga agreed to a formal alliance.
Zuckerberg says that if the company is going to make an investment like this, "we want to have an understanding that you won't just import our data — and that you try to contribute back. We’re working through that."
Facebook doesn't want to give its data to Ping without reciprocity?
If this sounds familiar that's because it's the exact same issue that Facebook got called out for by Google just a week ago. Google disabled Gmail contact export into Facebook (which FB later hacked) because Facebook won't share its contact data with Google.