The evidence is the fact they ask for it. And my response always to the "what are you worried about" why don't you publicly post your contacts and all their numbers? Why not post your home address I mean anyone can see where you live around you right, while we're at it the ssn next? Where do you want to draw the line at privacy? Personally I draw it at need to know, and there's no reason Tapatalk needs access to my contacts, even if it is only to verify an account. I can put in an email and password like everything else to verify an account. Like I said everyone sees things differently.
I don't use Tapatalk because I always find it garbage to use as it doesn't follow the flow of how I is the forum. That's just me personally though and I know that. Nothing to do with permissions.