I have very specific requirements starting in the ad itself, to weed out unwanted tenants.

Even if you are in an area where people don't care, it will still call attention which will be unwanted by your assailant.

I get dozens of unwanted spam texts and calls from them daily and there is no way to stop it.

If you didn't factor in the expense of a PM, you could find yourself in a situation where you have suddenly gone from cash flow positive to cash flow negative, and you'll be unpleasantly surprised at having to come out of pocket every month until you are able to get rid of the property. 

We can print money in the short-term to remain solvent, but at some point that has consequences that are unintended and unpleasant for the standard of living we've grown accustomed to.   

If you're up to training and caring for an animal, a dog is an excellent deterrent against unwanted strangers and intruders. 

You know the current landlord game to get rid of unwanted tenants is to give them glowing references so we should go back two or more.

The letter to the attorney was basically a typed letter about how I can help their clients who are stuck with unwanted houses.

If he is truly deranged or mentally unstable (possible with neat/bacteria-free issues)....you may be able to send a contractor (or multiple contractors) over to the crawlspace and leave some unpleasant smells, take pictures, and look for indications of illegal drugs.

Sell unwanted stuff that you probably have around your place or your parents.