The seller would use this strategy when they don't have a lot of equity in the house.

I’ve tried tru people search when I was D4D last week, and didn’t find a valid number out of the 20 houses I found 

Here's how to pin a house and the information it shows. 

You will need a local attorney to close on a house.  

One is house hacking. 

Building a sport court will run like $30 grand, but would increase your rental value. a 6bedroom 4 bath house with a sport court, hot tub, fire pit, mini golf, arcade etc. will most likely crush it because it's cool.

Occasionally if they have other assets maybe she can keep the equity of the house and he gets to keep his full 401k or something like that.   

If you don't pay off the loan, you lose the house, the seller gets a foreclosure and you probably get sued.

Finally, even with a substantial discount, the house may not be worth it.

Only other wild card is if they destroy the house on the way out.