How does Google 'see' Facebook shares?

[brianspatterson]

With Rand's new post about the correlation between FB Shares and rankings, I wanted to ask... How is Google able to see what links are being shared?  Does the profile have to be public?  Or do they get anonymous info direct from FB as part of some deal?

[wissamdandan]

We can get these info threw this API so Google

http://graph.facebook.com/http://www.seomoz.org