However, in my quick drive by the town there were some parts that were way better than others and the transition happened quite swiftly.

Emotional support animals is a major scam in our business and as a result cases like this need to be dealt with swiftly. 

Marshall & Swift and Boeteck are two of the providers. 

Thankfully the city intervened swiftly and the structure was taken apart and the plants removed who knows where but outside of a public eye. 

It must be a NE thing, because in IN we don't have anything like this.I would contact your attorney to find out how to handle this in the future, its my opinion that the 1st day I notice someone new living in the home I will find out was is going on and start playing hardball instantly be calling the police if I can't handle the situation with the tenants immediately.I have to believe that these new people are considered visitors in the eyes of the law if they are not on the lease and do not have permission from the landlord.Sorry to hear your experience, it think this proves that we have to act on these problems in a swift and harsh way when it starts.

Any attacks/resistance that gain any social movement will probably be swiftly followed with harassment and audits from the IRS. 

How could I swiftly and legally evict them from a property of mine, even if I have no legitimate reason other than my need to save money on my diet?

With that said there must be a swift way to analyze 2-4 unit multi-families. 

With few exceptions, it's landlords not acting swiftly and correctly within the law that makes CA evictions takes months instead of weeks.  

Be fair, firm and swift when dealing with tenants who violate the terms of a rental agreement.