Information my friends have is something I've had to accept letting go. I once resisted signing up to Viber because it required that I upload my entire address

Information my friends have is something I've had to accept letting go. I once resisted signing up to Viber because it required that I upload my entire address book. However, I found out how many of my friends are already on Viber, which means the likelihood that Viber didn't already have someone's contact information was very low. It also meant Viber already had all of my contact information. Another scenario is Facebook's tagging. Even if I don't confirm all (or any) of my friends' tags on my face, the fact that they manually tagged the face as mine likely counts a lot for FB, so that battle is already lost.