A simple way would have been to file elder abuse charges against these homeless people mooching off the person in the house and have them locked up.The things you were mentioning definitely sounds like criminal and willful abuse.

Depending on one’s perspective, this amendment to the injunction statute either eliminates some of the previous uncertainty for contract-for-deed cancellations or creates new uncertainty.Due in large part to the decline in residential real estate sales prices and the number of homes acquired from foreclosing lenders that are being resold on contracts for deed, there has been a rising concern about abusive or predatory practices by contract-for-deed sellers, their often total lack of compliance with both federal and state laws, and the general public’s lack of understanding about how contracts for deed work.

In other words you are not 65+ years of age and investing your life long earned savings for the first time (alluding to elder abuse for exemplary purposes only), thus you are expected to know better.

Gurus charge about $1,500 for weekend 1, $5,000 for the next course, and $25,000+ if you want to ride around on a bus with a has-been reality TV star.   

Most tenants assume 1-months rent for Sec Dep is a given, so some don't even mind losing it; But if 2-months is the limit, that may be enough to motivate a tenant to care more than usual.And finally, become (somewhat) comfortable with the possibility the property will be used or abused at some point. 

In order to permit tenants to adjust to the possibility of unregulated rents, and to address the potential for abuse of the owner-occupancy exemption by landlords who are motivated to move into a property to gain an exemption just to increase rent and not to reside in the property, this exemption should not take effect for one year after the amendment to This chapter exempting these rental units is adopted, or one year after the landlord begins owner-occupancy, whichever is later.I'm not sure you answered my specific question, but you have brought the above paragraph to my attention which looks like it directly applies to me NOW being exempt from Oakland's rent control and the "Just Cause for Eviction Ordinance" since I moved back in and Owner occupy one of the two units.

White color tenants that pay rent on time electronically and don't abuse the houses.

There is a park in my area that will not rent to sexual offenders.  

I certainly don't discriminate from someone who isn't going to abuse my home with kids and pets!  

Oppression through abuse of powers is a huge issue world wide.