This link should work for another day or so: https://developers.app.net/reference/make-request/migrations/

Short version, they let app devs restrict scopes of pre-scope tokens via Web config interface (scope downgrade) and apply more limited extended scopes to new grant requests as well.

Only ran into it today while hitting API to save my followers/ing. Tempted to grab everyone's to see what the social graph of follows ended up looking like, but not tempted enough to spend my limited dev time on it. Would rather look forward than back. :)

//