As someone who's been building an adblocker for the last 6 years: yes, there's plenty of proof in the devtools console on more websites than you'd think.

Fingerprintjs [1] is a well known one that gets a lot of use. And if you check EasyPrivacy, you'll see the rules to block it [2] have been in place for a long time.

[1] https://github.com/fingerprintjs/fingerprintjs [2] https://github.com/easylist/easylist/blob/132813613d04b7228c...

From over a decade ago, a paper on then-commercially-available browser fingerprinting tech, including a study of its deployment in the wild:

https://dl.acm.org/doi/10.1109/SP.2013.43 Nick Nikiforakis, Alexandros Kapravelos, Wouter Joosen, Christopher Kruegel, Frank Piessens, and Giovanni Vigna. 2013. Cookieless Monster: Exploring the Ecosystem of Web-Based Device Fingerprinting. In Proceedings of the 2013 IEEE Symposium on Security and Privacy (SP ’13).

Why do you think a porn site was trying to access MIDI devices? To play some smooth jazz?

https://www.obsessivefacts.com/images/blog/2020-04-04-the-ja...

https://news.ycombinator.com/item?id=23679063

Iovation is at least one companies script I know that the financial sector tends to use to get some fingerprinting on. Youngsters, please don't be skeptical. Surveillance hellhole-wise, fingerprinting is and will remain a perennial corporate favorite thing to do.

Yes. I wrote the code that did it, way, way back when.