This is literally the plot to Trillion Game.
DarkWinterNights
Can barely comment on this stuff anymore because of the literal horror being inflicted
I'm glad I read to the end; your comment got me laughing and checking my life insurance
Privacy focused browsers can help (but don't fully resolve). Not to redo the work of others, copy/pasta:
What makes fingerprinting a threat to online privacy? It is pretty simple. First, there is no need to ask for permissions to collect all this information. Any script running in your browser can silently build a fingerprint of your device without you even knowing about it. Second, if one attribute of your browser fingerprint is unique or if the combination of several attributes is unique, your device can be identified and tracked online. In that case, no need for a cookie with an ID in it, the fingerprint is enough.
A couple of useful articles:
https://en.wikipedia.org/wiki/Device_fingerprint
https://blog.torproject.org/browser-fingerprinting-introduction-and-challenges-ahead/ (Excerpt above)
https://onlinelibrary.wiley.com/doi/10.1155/2022/3363335
There's also a number of interviews with white and red hat hackers who delve quite deeply into the subject and how they've used this telemetry to go after black hats (mainly to emphasize that even with some degree of sophistication this can be difficult to evade, especially when compounded with other methods and telemetry already modelled against your identity).
Frankly already a moot point - your browser fingerprints are already uniquely identifying (even before IP, cookies, and backend analytics). Realistically, tho, just more info for them to sell, leak and then eventually pay $0.25 per person in Google Play credit in the class action settlement.
As you say, even with Internet connection, LLMs only infer. The software you run it on (or online) is a different story, and it's literally already the case with everything else for decades (although it is getting worse).
We weren't upset enough when Google started scraping everyone's emails, or how Meta/Amazon/Google/Microsoft/ByteDance track all your Internet activity right now via browser fingerprinting.