What happens if you've never been a Meta user? I have never had any kind of business relationship with Meta (so far as I know), and have never agreed to any contract or terms of service. What can I do, under US law, to minimize what they store about me and my behavior, or at least keep tabs on them?
Is this rhetorical? Nothing. Every website that adds their code will be tracking you. Every friend, acquaintance, or anyone that you’ve shared your contact with for what ever reason that has given them access to their contacts has provided your info for you. There’s nothing you can do about it.
At the rate we’re going, it will soon be law that you have to allow them to track you. The Zuck just hasn’t figured out yet that if he writes larger checks, he can get an executive order that would benefit him.
Great, what about people that cannot install blockers?
What about sites that sell the data they collect to Meta? If you think Meta's trackers are the only way Meta collects data, then you just need to learn more about data collection.
"What can I do, under US law, to minimize what they store about me and my behavior, or at least keep tabs on them?"
"...Nothing"
"Nonsense, and the article addresses this. 'Block Meta’s Trackers'
The parent said nothing could be done. I say that's nonsense and listed a thing that could be done. You respond it's not nonsense and then list the same thing I mentioned.
Then you have a very easily confused process yourself. They did not make such a declarative statement as you suggest. They just said that blocking them is still a good idea even though it's not going to stop Meta from knowing about you. Being able to see the details in someone's comment is easier when you don't have a preconceived agenda
If you live in one of the states that has strong privacy regulations send Meta a data deletion request. Or if you are curious about the data they have on you, send them an access request to get a copy of your data, and then a deletion request.
In some cases Meta ignores these requests. If that happens to you then complain to the state regulator. Both sending requests and complaining is easy as sending an email / filling in a form.
I use uBlock Origin and Privacy Badger which should mitigate tracking via the "share with Facebook" button. I also use Cookie Autodelete (except for whitelisted domains) which should make tracking via cookies next to impossible. Users can be fingerprinted via other means, and I know my fingerprint is unique, so I try to make my fingerprint different every time. For this I use a UserAgent randomizer (which unfortunately breaks some sites (e.g. youtube), which then have to be whitelisted).
I think this should minimize the impact of their tracking, but surely the Hacker News crowd will now give me suggestions for improvement.
The option to accept or decline cookies is, unfortunately for parent, not necessarily legally enforceable outside the European Union and the United Kingdom. There might be an argument that Meta cannot track a user after explicitly offering the ability to opt-out (promissory estoppel?), but I rather doubt it.
In the EU/UK, the argument is academic, as the GDPR requires ongoing consent to track a user: you can't sign away your privacy in perpetuity.