Provided, of course, that the landlord isn’t discriminating based on any protected classification (i.e. race, religion, gender, etc).However, some individual cities (like Seattle for example) have passed ordinances that require landlords to use a “first come, first served” type of system and basically accept the first qualified applicant that applied.  

Chicago has 14 protected classes for Fair housing-1-Race2-Sex 3-color 4age 5-Religion 6-disability 7-National origin 8-ancestry 9-Parent/parental status 10-Sexual orientation11- Gender identity 12-marital status13-military status 14-source of income You need to be careful on the language you use for advertising a rental.

The plan originally is to lease out geographic religions to investors who already use bird dogs or want to use bird dogs and want an easy painless way of recruiting, training, managing, communicating with and paying them.I'm onto something.

Of course, it is always safest/best to avoid discrimination against protected classes (race, religion, national origin, familial status, creed, sex) in order to avoid breaking the law, though there are even exceptions there (i.e. if you lived in the house, for example, there are some exemptions). 

It's like science and religion.

No one would ask on an application form what the applicant's sexual orientation, religion, race is etc...so why would you ask about ESA? 

The Fair Housing Act is what applies to privately owned property (with the exceptions Bruce listed above) and it forbids discrimination against prospective tenants because of their disability as well as race, religion, sex (including gender identity and sexual orientation), skin color, familial status, and national origin. 

I swear on all the religions that they dont.

Of course we have people who are unhappy with us (like every other business, non-profit, politician, author, country, fictional character, book, religion, idea.....)

Property owners/managers are subject to the Federal Fair Housing Act, which prohibits "any preference, limitation, or discrimination because of race, color, religion, sex, handicap, familial status, or national origin, or intention to make such preference, limitation or discrimination."