As per case facts, a government corporation attempted to evict a long-term tenant from its premises under a federal law for public property. The tenant claimed protection under local rent ... control laws, leading to a legal dispute over which law took priority for old tenancies. The question arose whether the federal law for evicting unauthorized occupants applies to tenancies created before that law existed. Finally, the Supreme Court held that the federal Public Premises Act overrides local rent laws to ensure the speedy recovery of government-owned property. The Court overruled a previous case that had limited the law's reach, declaring that once a tenancy is legally ended, the occupant is unauthorized regardless of when the lease began.