Anyways, what can be done probabably will be done, for whichever reason because it's getting cheaper and cheaper.
And then the next leak happens.
And somewhere on some site like Have I been owned?, or in a torrent there is a comma separated list with many, or even all of your former pseudonyms connected with your current address, social security, drivers license, younameit.
Gotcha!
Stylometry is a thing, sure. But it's rarely accurate enough to use on bulk archives in an automated way, especially when archives come from different domains (eg, technical vs social writing).
It's useful for identifying possible alternate authors plays attributed to Shakespeare[1], but a lot less useful for trying to tie a reddit identity to a github profile.
Anyways, what can be done probabably will be done, for whichever reason because it's getting cheaper and cheaper.
Crawling and storing is cheap, but analysis is harder. Automated spell checking ("probabably" above not withstanding!) and auto-complete means stylometry is even less useful now.
Source: myself - I work in natural language processing, and have talked to people applying these techniques.
[1] https://www.frontiersin.org/articles/10.3389/fpsyg.2018.0028...
This is a fantasy spurred on by too many dark mirror episodes, nobody does stuff like that for the hell of it. Storing the amount of data we're talking about is expensive. Collecting it is expensive. Processing it is expensive. There's little money to be made with it, but it sounds really good if you don't think too hard about it. It's illuminati conspiracy mumbo jumbo for nerds.