Even better: leave the face browser on by default, but by default leave the list of users to appear in it _empty_. Then the installer folks could do something very cute:
- if there's a webcam available on install, then ask the user if they want to have a pic taken for the face browser, and if they say yes, then take it and put the user in the face browser list. By keeping a separate list of face browser users you solve the local user problem and the $HOME problem (when the user logs in, and whenever the user updates their face pic, update a cached copy of their face pic).