Commuter data is good, so is foot traffic. Data sets centered around health and income or quality of life can be beneficial as well. The game is to use publicly available information about your person to tie them conclusively to set of entries in an 'anonymized' data set.
If you aren't at least investigative journalist tier or the resources you need cost too much/require a corporate presence, then hire someone to do it for you who already has the pipeline set up. PI's have been available to Joe Q. for years and they still are. This all just makes them even more efficient.
Use a list like this as a starting point.
https://www.oag.ca.gov/data-brokers
Commuter data is good, so is foot traffic. Data sets centered around health and income or quality of life can be beneficial as well. The game is to use publicly available information about your person to tie them conclusively to set of entries in an 'anonymized' data set.
If you aren't at least investigative journalist tier or the resources you need cost too much/require a corporate presence, then hire someone to do it for you who already has the pipeline set up. PI's have been available to Joe Q. for years and they still are. This all just makes them even more efficient.