Not at all, the author uses Tor to anonymize their location and probably system footprint. If you read the response the only "acceptable" phone number is a mobile phone. It de-anonymizes you because mobile providers hand out this sort of information for cash.
The only reason for the phone number request, based on the requirements of what kind of phone numbers are acceptable (no VOIP, no landlines) is that they want to be know where this user is when ever they use the service, or how to locate them.
> It de-anonymizes you because mobile providers hand out this sort of information for cash.
No, the mere fact of the phone companies even having that information de-anonymizes you.
Suppose someone doesn't like what you have to say, sues you, and subpoenas the phone company for your information - that they don't sell it won't save you. Or you say something that upsets the phone company, its parent company, or one of its subsidiaries. It launches an internal investigation, and finds you [1]. All without selling or even sharing your information.
My comment was linking to a page explaining the term anal-retentiveness, which the parent poster clearly isn’t aware of, and is apparently flagged so no one can see it; what are you talking about?
