It's done by telcos and data brokers. Every US citizen has a detailed profile compiled about their personal lives that the US government can access at will. Google and Meta are the new kids at the table of a long running game.

> the US government can access at will

Warrants are at will? Nope.

You don't need a warrant to get data from a third party. The government just asks and if the they enjoy receiving special treatment and other favors in the future they comply. That's why the USG likes to have this collection devolved to private entities.

> You don't need a warrant to get data from a third party.

https://policies.google.com/terms/information-requests

"In all cases: Issue a subpoena to compel disclosure of basic subscriber registration information and certain IP addresses

In criminal cases:

Get a court order to compel disclosure of non-content records, such as the To, From, CC, BCC, and Timestamp fields in emails

Get a search warrant to compel disclosure of the content of communications, such as email messages, documents, and photos"

Some 3rd parties require warrants. I tend to think that this is the rule rather than the exception.

Google isn't the one holding the keys to the castle. Data brokers predate them by decades. The primary reason why the US has weak data protection laws is because the government doesn't want their activities to be encumbered.

Your assessment is only correct if the warrants are not obtainable at will.

Edward Snowden and the FISA court say hello.

If you don't know about it, they don't need a warrant.

Says NSA.

> US citizen has a detailed profile compiled

partially true but fodder for schizophrenics and compulsive obsessions.. A truer picture is harder to convey in a few sentences.. however as a US citizen I believe that an uneasy truce has been established via law in the USA since inception, between those casually referred to as "Law and Order" who genuinely believe that governance means record keeping and monitoring, and others who do not. Unfortunately for the "others" that includes genuinely bad actors who seek to use rights to evade detection, or those too stupid or simple to think about these things at all. Meanwhile, the Net has given magnificent, grandiose power to build and use surveillance, which they have done. ill wind blows