I had some very ugly experiences setting up one for my cousin (I stupidly didn't lie and registered her as being from Uruguay and under 18), which made the phone behave like a brick ("sorry, no apps available in your country", "sorry, you have to be over 18 under laws from another country to use most of the features of this phone").
Changing the Live account did not work, I had to reset the phone and create another account for her, lying about her age and country so the phone could work properly (she wanted to use Skype and WhatsApp, not exactly the most demanding use case).
That stupidity turned me off Windows Phone for the foreseeable future (although the hardware is top-notch).
That only applies for the United States and I guess most European countries, but it's not universal.
http://en.wikipedia.org/wiki/Age_of_majority
For example, here in Uruguay, there's a distinction between minors up to 16 years, then they can enter some contracts (for example work contracts, I don't know where downloading apps falls), and they become full adults at 18.
In the U.S. there are some restrictions up to 21 years old, but they can drive at 16 (!). My cousin was 17 at the time I was setting up her phone, I'm not sure, but I guess she might have been legally able to enter a contract with Microsft at the time.
Google is more lax with its settings, or has better lawyers. Also, if you move to another country, you CAN change your settings (it's extremely ridiculous that Microsoft doesn't let you do that).
I can totally understand that Microsoft doesn't want to go over the minutiae of every small nation to see whether someone is eligible or not to enter a contract.
I wonder what Firefox OS will do with all these legal restrictions (offload to the app developers?)
All recent MacBooks I have seen insist rather hard to be paired with an account and a credit card number. I have never done the initial setup of an iOS device, but I would have assumed that it was the same or worse.
iPhone 5 + iOS 6: doesn't know a thing about my credit card, and never will.
Irrelevant as those users will not care and just punch in their credit card if asked.
The identity part? I have an account, so yes, some sort of 'identity' is revealed, but that doesn't relate to the credit card part.
They still do not know a thing about any of my credit cards, from initial setup to everyday use.
It's been a while since I set it up, but if I recall correctly you can create your "Apple ID" online and select 'None' for the credit card, then you sign in on your device with that account.
When you're creating an account on the device, I think it may force you pair a credit card though.
That is completely untrue, unless you are seeing some weird install of OS X. But you're not, you're making stuff up.
You can skip the product registration and you can skip signing in with your Apple ID and essentially have an "anonymous" install with little effort.