We use an information exchange. Once you know 2-3 things about someone, you can find out 5-6 more things about them.

These information exchanges are legal, compliant, and widely available. An example of a very public and expensive one is http://pipl.com/

Cigna Transparency in Coverage This link leads to the machine-readable files that are made available in response to the federal Transparency in Coverage Rule and includes negotiated service rates and out-of-network allowed amounts between health plans and healthcare providers. The machine readable files are formatted to allow researchers, regulators, and application developers to more easily access and analyze data.