My old manager wanted me to install WhatsApp. WhatsApp wanted to access my phone's address book so that it could upload all of my contact info to their [Facebook's] servers. I denied it, and it refused to work. I didn't want to share my contacts - I just wanted to communicate with a specific set of people. The only workaround I could find is back up and delete all my contacts before letting WhatsApp rummage through my address book.
I wouldn't say this practice is very "consensual".
I wouldn't say this practice is very "consensual".