How does Google gather social graph data?
The Social Graph API returns data from an index of public web pages and publicly declared relationships between people on the web. An example of a public user account is your MySpace profile page. An example of a publicly declared relationship is a hyperlink pointing from your LiveJournal page to a friend’s.
The Social Graph API returns data from an index of public web pages and publicly declared relationships between people on the web. An example of a public user account is your MySpace profile page. An example of a publicly declared relationship is a hyperlink pointing from your LiveJournal page to a friend’s. Our crawler scans for links that: • indicate that a set of web pages are related to a particular user • indicate public friend relationships around a public web page We accomplish this by indexing open standards like XFN and FOAF, which annotate links to describe friend relationships.