Final answer:
Blockbusting is forbidden by federal law, specifically the Fair Housing Act of 1968, as it promotes fair housing and prevents discriminatory practices in the housing market.
Step-by-step explanation:
The practice of blockbusting, which involves real-estate agents and speculators playing on white fears by announcing their intention to sell a home in an all-white neighborhood to a minority family, is forbidden by federal law. It was outlawed by the Fair Housing Act of 1968. This law was enacted to prevent discriminatory practices in the housing market and promote fair housing for all individuals, regardless of race or ethnicity.