Considering all the apps that like to use the phone numbers and emails to help new users find their friends using the app it's a difficult decision. I think a

Considering all the apps that like to use the phone numbers and emails to help new users find their friends using the app it's a difficult decision. I think a good compromise would be allowing an app access to phone numbers or emails without the rest of the information, eg whose number that is, their street address, etc. Then, giving your own number when you sign up could be an option. That way a new user's app could connect them to those friends of theirs who have opted to attach their name to their number.