Answer:
blockbusting
Step-by-step explanation:
The Fair Housing Act prohibits discrimination based on race, gender, age, color, marital status, disabilities, marital status, religion, or national origin.
Blockbusting is illegal and it happened (hopefully doesn't anymore) when a real estate agent tried to trick white homeowners into selling their houses using the threat that protected classes (generally black minorities) are going to live next to them and literally "invade" their neighborhood. This invasion would result in higher crime rates and a steep decrease in the price of their homes.
Then the same real estate agents would sell vacant houses to minorities at higher prices for the privilege of living in a white neighborhood.