What is "retaliatory eviction"

n. an eviction in reprisal for the tenant's good-faith complaints against the landlord; illegal in many states

In American landlord–tenant law, a retaliatory eviction is a substantive defense and affirmative cause of action that can be used by a tenant against a landlord. If a tenant reports sanitary violations or violations of minimum housing standards, the landlord cannot evict the tenant in retaliation.