It comes from the telcos directly (think Sprint phones with custom OS installs), it comes from popular mobile SDKs (e.g. why Yahoo bought Flurry), and it comes from apps who simply sell the data directly.
There is one journalist who actively covers this sort of PII/data-selling world: Joseph Cox at Vice [1]. The only US-based legislator who actively fights against this is Senator Wyden.
* https://www.advanresearch.com/
* https://www.placer.ai/
* https://www.onemata.com/
* https://www.safegraph.com/
It comes from the telcos directly (think Sprint phones with custom OS installs), it comes from popular mobile SDKs (e.g. why Yahoo bought Flurry), and it comes from apps who simply sell the data directly.
There is one journalist who actively covers this sort of PII/data-selling world: Joseph Cox at Vice [1]. The only US-based legislator who actively fights against this is Senator Wyden.
[1] https://www.vice.com/en/contributor/joseph-cox