I disagree. Well, strictly speaking, asking for identifying information might be OK, but storing it or communicating it to other parties is not, at least not without some justification why that is needed.

Control over your personally identifiable information is similarly important in the modern world as is control over your property, and where the two come into conflict, appropriate solutions have to be found.

Agreed regarding the property analogy, but you regularly give up your property for the use of a service.

It is not immoral to request someone's property as a form of payment for use of a private service.