Anonymized clustering and graph tracing, to identify the geographic interconnectedness (or lack thereof) of criminal organizations.

It would be very useful to the FBI to identify whether they're looking at a solo criminal enterprise or a multi-state organization.

I'll gripe about intel community abuses as much as anyone else, but it's a lack of imagination to say there are no valid, privacy-preserving uses for this.

Historically, Google rightly identified PII as the goose that lays golden eggs, and so voluntarily put safeguards in place around it to prevent individual abuses from killing it.

The FBI could do the same. I doubt it'd be effective, given political pressure from threats and constantly changing leadership, but it's technically possible.

If it's publically for sale is it really circumventing due process?

Do the police need a search warrant to lookup who owns a property, or leverage the white pages?

It is PUBLIC information. That is not circumventing anything. The issue here is NOT the FBI. It is the DATA being PUBLIC information.