Comment by noahjk

Very similar to sites like LinkedIn, which ask you to share your personal info & contact list.

I don't want to share my contact details, but the second someone I know decides to opt in, I lose all rights to my own data as they've shared it on my behalf.

Maybe they have other info, such as birthday, home address, other emails or phone #s, etc. stored for me, which is all fair game, as well.