I have a few stories identical to @Matt Pritchard . 

The mail boxes are on your property and it has been verified by previous owners.

Now, you could possibly cause some problems for the agent who didn’t get the broker’s signature, which as you know you should have verified, and perhaps put some pressure on the brokerage by complaining to their state real estate commission, your only source of possible recourse, but not likely.

Verify the the tax sale was done correctly, all parties notified. 

But I would be circumspect about how I requested the records (need them for personal research project), how the information appeared when disseminated (all indications that it came from the State would be removed), and how I phrased my interactions with property owner's who were identified through use of public records (I'd never mention that the owner's identity or address was obtained from the State or County, only that obtained the information legally at considerable cost).

I called and verified.

By Day 20, had an overseas hacker stolen their identity and used it to open multiple credit cards in their name?

I have a potential property, the seller is motivated and verified there aren’t any back taxes, and the home is owned by him, no banks involved.

All 12 units are identical layouts. 

Race, color, national origin, gender, gender identity, sexual orientation, disability, ancestry, genetic information, marital status, veteran or active military status, age, familial status (i.e., children), and source of income (i.e., Section 8 voucher)There are two exceptions to age discrimination.  1. 55+ communities are allowed to discriminate against those younger than 55.2.