[ggggtez]

>is granular location data illegal

Generally speaking, there are no laws against merely possessing data, unless the data itself was the result of a crime.

Maybe you mean selling the data? That's nuanced. It seems to be illegal for phone-companies to sell your real-time cellphone location... but historical data? App developers instead of phone companies? The devil is probably in the details in terms of what constitutes a crime and what is just shady business. See [1] where AT&T sells your location data but insists it's not technically illegal (but claims they stopped selling it anyway).

Many companies try to anonymise this data anyway because it's good business to not piss off your customers.

[1] https://www.theverge.com/2019/5/17/18629553/att-t-mobile-spr...

[PeterisP]

The article is about Norway, and there are laws against merely possessing data, namely the GDPR. To be specific, "merely possessing" private data (the granular movement data would qualify) by companies for business purposes is illegal by default - there are many options that give a legal basis for processing, and many of them do not require the user's consent, but it's upon the company to demonstrate what gives them the permission to do that, and having no justification (if the company "just has it") means that the processing is illegal. And even if the company has a legitimate reason for processing as such, doing so "without your knowledge" is generally illegal, as even where consent is not required, they are required to inform the data subject about the purposes of processing their private data.

It's not about selling data - purchasing the data or having it or using it also are covered.

[ggggtez]

The above poster's question was specifically about the US.

GDPR does not cover the US. Europe has more privacy laws than the US does.