[quote=spdrun]Are there any state/local laws specifying minimum square footage or rooms per occupant?[/quote]
IN california I think the rule is 2 persons per bedrom + 1 more person.
So, a 4-bedroom can hold 4*2 + 1 = 9 people. Exactly the number here.
Based on the facts posted I think this is an obvious case of discrimination. The only question is whether the landlord was ignorant enough to put the reason in writing, in an email or a voice mail message (or post it on a blog).