There is this big electronics store in NYC - I bought something small (batteries or something) and at the checkout, the cashier refused to bill me, unless I gave my phone number or email. When I asked why he needs that info his answer was "so we can verify when/if you return the product", and he had no answer when I said "that is what the bill is for, isn't it?". Unwilling to hold up the line, I left without purchasing anything.

Point is, no one before me had issues with giving that info, no one bothered to ask. Unless many people start asking questions, nothing will change, and I don't think most people care.

At the high school level, kids should be taught topics like privacy, civil rights etc - that might help at least a bit