But in the real world,your contacts never told you "feel free to upload my name and all my phone numbers wherever you want, so we can be linked by some cloud se

But in the real world,your contacts never told you "feel free to upload my name and all my phone numbers wherever you want, so we can be linked by some cloud service to improve their click-through rates". An app that uploads your contacts is violating the privacy of your friends, even if it asks you about it.