I keep a food supply on hand for emergencies (mostly I think of hurricanes) but also in case of a quarantine situation, for a biohazard or virus pandemic.
It has crossed my mind that if a flu pandemic would ever break out, they would probably try to use the concentric circle quarantine model, and would probably have at least the police (but no city really has a police force large enough) or the military/National Guard enforce it.
IMO, it is the only way to try to contain a true epidemic.
See FR thread
http://www.freerepublic.com/focus/f-news/1495712/posts
I'm with ya Dawn,
I keep my Hurricane kit ready year round for any emergency. That includes food, gas, etc. I know it sounds like a paranoid approach, but having some security never hurts.