I think you might be somewhat confused over the meaning of private. My medical history is private. That means that I have the right of control over how that information is used and to whom it can be shared. I might choose to share it with my doctor because I trust them* and I am comfortable that it is beneficial to me. I might permit my doctor to share that information with a specialist. I might permit the specialist to share a very small portion of that information with my employer to assert fitness to work. Add my health insurer or hospital or ..... As you can see, it is no longer a secret, but it is still private. There may even me some reason to share this information with apps on your smartphone. Healthcare claim apps, flappy birds, it doesn't make a difference whether you think the app has a reason to know. The question is about informed consent and control. No more no less. So if someone chooses to let Google track every time they are at home or work or school or the shops or a place for their bowel movements, as long as they are providing informed consent, who are you or I to tell them they can't. Sharing with that company may be unwise, but that doesn't mean they don't have the right to choose who to share their private information with.
*that is independent of whether that party is deserving of that trust.
Biting the hand that feeds IT
