> They tend to attempt to do this anonymized. How successful they are in anonymizing that is very much so up for debate.

Yeah I think the big thing to push or talk about is that there is no such thing as "anonymized".

There's only such as a thing as "can only be identified as X many people". Like for a given dataset you can make any data point correlated to 1 of say 50 people. If somebody is anonymizing data and they don't provide a k-anonmizity [1] you should just assume it's 1:1 and effectively not anonmized.

[1]: https://en.wikipedia.org/wiki/K-anonymity

> They tend to attempt to do this anonymized. How successful they are in anonymizing that is very much so up for debate.

    let anon_id = md5(SSN);

In the good old days, if you were found to be informing on your neighbors to hostile powers, you were liable to find yourself in a mass grave when the political winds shifted, or even sooner.

But now it's so convenient and discreet and common, we think nothing of it. Plus, Google and Apple and Facebook and their partners and everyone they sell data to are our friends, not enemies :)