Housing discrimination
Treating a renter unfairly because of who they are. New Jersey's Law Against Discrimination bars landlords from doing this based on traits like race, creed, national origin, sex, gender identity, disability, familial status, or source of lawful income.
New Jersey example
An apartment manager in Newark turns away an applicant because her income comes from disability benefits instead of a paycheck, or says a unit isn't for families with kids. Both can violate the LAD. Complaints about state law violations can go to the NJ Division on Civil Rights, and a landlord can face a penalty of up to $10,000 for a first offense.
Official source
This is a plain-English summary. Rules and dollar amounts change, so check the official source or a professional before you file or sign anything.