Each profile image has a FACE number and link directly to the corresponding user profile. Mark Zuckerberg is of course FACE #1. The Faces of Facebook does not offer information from private profiles and the order in which FACE numbers are allocated corresponds to the order of account creation on Facebook.
The news of such an application raised privacy concerns especially among existing Facebook users. When contacted about this issue Natalie Rojas had the following to say: "Relax. We're not breaking any Facebook privacy rule because we don't store anyone's private information, pictures or names".
The web developer of this impressive mosaic continued by explaining that users already logged in his/her Facebook account will have a far greater experience while visiting "The Faces of Facebook". The site has the following URL: http://app.thefacesoffacebook.com/