[gweinberg]

For a fingerprint to be useful it must not only be unique but also persistent. If I have a process that randomly installs and deletes wacky fonts, I'm unique at any given time, but the me of today can't be linked to the me of tomorrow, right?

[internetter]

Point still taken, however you can only really check if a given font is installed, not obtain a list of all fonts. Thus, installing a wacky font is pointless as the fingerprinter won’t bother to check that particular font. There is queryLocalFonts on chrome but this requires a permission popup.

[disambiguation]

Correct, however:

> By following users over time, as their fingerprints changed, they could guess when a fingerprint was an ‘upgraded’ version of a previously observed browser’s fingerprint, with 99.1% of guesses correct.

https://coveryourtracks.eff.org/static/browser-uniqueness.pd...

https://mullvad.net/en/browser/browser-fingerprinting

[gruez]

>If I have a process that randomly installs and deletes wacky fonts, I'm unique at any given time, but the me of today can't be linked to the me of tomorrow, right?

See: https://xkcd.com/1105/

Services with a large enough fingerprinting database can filter out implausible values and flag you as faking your fingerprint, which is itself fingerprintable.

[nativeit]

The problem we’re falling into under this (ostensibly accurate) point is when we start making this a game, where fingerprinting is either “100% effective and insidious”, or “can’t be 100% certain 100% of the time, so it’s ineffective and nobody will use it against me”.

The point is that a sufficiently motivated actor could use a very broad array of tactics, some automated and some manual, to identify, observe, track, and/or locate a target. Maybe they can’t pin you down with your browser fingerprints because you’ve been smart enough to use tools that obfuscate it, but that’s not happening in a vacuum. Correlating one otherwise useless datapoint that happens to persist long enough to tie things together at even low-ish confidence is still a hugely worthwhile sieve with which to filter people out of the possibility pool.

The problem isn’t that it doesn’t affect most average people, or that it it’s terribly imprecise. The problem is that it’s even a little effective, while being nearly impossible to completely avoid. It’s also a problem if that’s used by a malicious state actor against a journalist, to pick a rather obvious example. Because even in isolation, this kind of violation of civil liberties necessarily impacts all of society.

The public should be given more information and control, broadly speaking, for when they are asked to trade their rights for convenience, security, and/or commerce. In particular, I think the United States has allowed bad faith arguments against regulatory actions and basic consumer rights so corporate lobbyists can steamroll any chance of even baseline protections. It would behoove all of us to be more distrustful of companies and moneyed interests, while being more engaged with, and demanding of, our governments.

[NewsaHackO]

But they still wouldn't be able to confidently connect his different fingerprints to the same individual, just that he is one of a group of individuals who fake their fingerprints.

[gruez]

It would depend on what your existing fingerprint is. If you're using some sort of rare browser/OS/hardware combination (eg. pale moon/gentoo linux/IBM thinkpad) it might be worth spoofing, but if your configuration is relatively "normie" (eg. firefox/windows/relatively recent intel or amd cpu/igpu)you're probably making yourself stick out more by faking your fingerprint.

[NewsaHackO]

The issue is that, especially on desktop, I doubt there are many fingerprints that more than 100 people have, given everything that they test. I would even suspect that most common desktop fingerprints are classified as bots.

[collinmanderson]

> If I have a process that randomly installs and deletes wacky fonts, I'm unique at any given time

Technically for fonts, there’s no API for listing installed fonts, so trackers have to check each font by name. Likely they won’t be checking super obscure font names.

That method might help for other signals though.

[poorman]

It's likely that yes, you will end up with an alias that links you because of a cookie somewhere, or a finger print of the elliptic curve when do do a SSL handshake, or any number of other ways.

The ironic thing is that because of GDPR and CCPA, ad tech companies got really good at "anonymizing" your data. So even if you were to somehow not have an alias linking your various anonymous profiles, you will still end up quickly bucketed into a persona (and multiple audiences) that resemble you quite well. And it's not multiple days of data we're talking about (although it could be), it's minutes and in the case of contextual multi-armed bandits, your persona is likely updates "within" a single page load and you are targeted in ~5ms within the request/response lifecycle of that page load.

The good news is that most data platforms don't keep data around for more than 90 days because then they are automatically compliant with "right to be forgotten" without having to service requests for removal of personal data.