The system for recommending names on Facebook can be considered prior art under some circumstances. This is the same as described above with one difference: Facebook uses a k of 2 (everyone that is 2 degrees from the user, or one degree from the user's friends). In this patent application the value of k can vary to different maximum degrees of separation. Since k is a tweakable parameter, I would say that Facebook's present system IS prior art. (You can view this when selecting find friends and looking at the list under “Discover people you may already know”.

The Circle of Friends (1999) as implemented on Llantrisant Online (2001) allows users to add friends manually and recommends 'friends' from genealogical data, increasing their reputation when they add them.