I was appalled when I went to install it and there was no way I could see to avoid handing 100% of my contacts to it.

Do people keep a private offline contacts list, or a clean phone just for this?

Or do folks just not care about giving away the mobile phone numbers (and addresses? email addresses? birthdays? other notes on the contact about kids names, etc.?) to an app?

Am I behind the times and everyone just knows none of this stuff is private anyways due to leaks etc.? Even if that is your attitude, it seems you are feeding more links to the graph someone else is maintaining. Did you get consent from every one of your contacts to do so?

I feel like I must be missing something here. Am I over-reacting or paranoid?