Advocates may do work like sending "testers" (people of different races, for example, but of similar employment and household income) to observe any patterns in how people are treated. But if all you have is a suspicion without hard proof, you'll have a more difficult time moving forward. "You can complain to one of the fair housing agencies," Scherer suggests. "In New York City, it’s the New York City Commission on Human Rights. At the state level, it's the state Division of Human Rights, and at the federal level, it's HUD's office of housing discrimination."