[randog]

I wasn't aware that New Orleans was federal government property.

According to CBS News on Aug 30: NEW ORLEANS, Louisiana -- Martial Law has been declared in New Orleans as conditions continued to deteriorate.

Definition: Martial law is the system of rules that takes effect (usually after a formal declaration) when a military authority takes control of the normal administration of justice.

Yes, the feds do have the authority to tell people where they can go in New Orleans.

[Maaxx]

Wrong. The federal government has no such constitutional authority.