I guess HN's pedantism will make me write a whole paper about what was supposed to be a simple example... Anyway, both the example of advertisement and health

I guess HN's pedantism will make me write a whole paper about what was supposed to be a simple example... Anyway, both the example of advertisement and health care data need to also provide privacy. In both cases the data should be considered sensitive and not public. In both cases, the data can be protected through blind signatures. [0]: https://en.wikipedia.org/wiki/Blind_signature https://en.wikipedia.org/wiki/Blind_signature