For the most part, contracts are signed by relatively new contacts (people not yet in my address book). E.g. new customers, partners, contractors, or employees.
I hope you'll get rid of this unnecessary intrusion into my privacy in the future. And, for what its worth, people who send around lots of NDAs, LIOs, term sheets, employee agreements and other sorts of contracts usually value their privacy.
And yes -- I understand that you say you won't be spamming my contacts or mining it for data. It's just that I don't know you.
Plus... most of the people I am faxing won't be in my contact address book. Those are usually to some random numbers. If you guys can remove the request for address book, it'll be a no brainer to sign up.
I don't trust you to be able to see my contacts, and I surely don't trust you with making changes to them.
Good luck with your service, I'm sure it's nice.