@dansup @loops considering how much information is likely in one's address book, and the unknown status of what would happen to the data if any third accessed the same, it has been my policy for years to never share my contacts with any app. And I resent the "not now" button, how about not ever?
I don't particularly appreciate when PEOPLE share my contact information without asking me, so I guard everyone else's information just as much.
It sure sounds like you're on the right path with this.