> 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.
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.
[1] https://www.zdnet.com/article/how-microsoft-tracked-down-a-s...