If they already make threats to sue for normal maintenance,  its not a stretch that they would just make more noise about having people walk through their house.

Stay involved, at the local and cyber level.

Press very hard on him since he is the road block, threats might help, remember he is a soon to be ex tenants and of no value to you any longer. 

  -  Households with children twice as likely to face an eviction threat, regardless of marital status- the Map of the eviction rates across the country- Their conclusion is 20% of renters struggle to pay rent.  

The notice comes with 0.5% monthly interest and the following threat: "Failure to pay will result in the cost becoming a tax lien against the property or a personal debt turned over to a collection agency."  

Gregg , I tried to respond to your threat re properties in Ohio but only pro's can respond where you posted.

He was making threats and demands, could have been Mr.

Generally when people turn like that and start going crazy and making threats that "you better do the deal or else", it's a scam and this is their last ditch effort to get your money.

The only real threat I see to the real estate market in the bay area is not the technology jobs leaving, but some sort of a major natural disaster like a magnitude 9 earthquake hitting the bay area, otherwise the real estate demand and prices will continue to hold up.I much rather spend my time and energy trying to identify a no name tech company that will have the ingredients in place to emerge and become the next Apple.

Perhaps too impulsively, I invested 20k to set up an Airbnb in an HOA governed neighborhood: one of the few left unregulated outside of Boulder, CO, and the neighbors just informed me that there are several clear rules I am breaking with my Airbnb Ads, he has found them and requested I stop at threat of calling in the HOA.