> Taxpayer data was also shared with Google, through its own tracking tools — though the firm told lawmakers that it never used the information to track users on the internet, according to the report.

So, they only store a unique id in their user tracking system, but they put the sensitive information in their ad targeting system, then join the data at impression time.

I guess it is good that they don’t stick PII in tracking cookies that they use to interoperate with third parties, but that is an extremely low bar.