H1N1 and the Role of a Notification System

Recent articles (here and here, for example) indicate the critical nature of communication during a public health emergency, as is the case with any other kind of emergency.
However, I would urge my few but valued and influential readers to be careful when using an emergency notification system in order to make people aware of your health department's actions in progress. You may create an emergency where there was none.
Case in point, I learned today that a municipal 9-1-1 center is using their notification service to call thousands of people to let them know about a flu clinic. I fear a disaster approaching. Some percentage of the thousands of recipients will think of this as a grave warning and will likely be concerned, agitated, or panic stricken. Some number of people will not receive the message (for any number of reasons, no system is perfect) and some number of those will be worried, agitated, or panic stricken. And those people will call and call and call the 9-1-1 center and the health department.
Rather than use their ENS, they should really use traditional broadcast media - radio, local TV news, and the local newspaper - to advertise the presence of the clinic and availability of vaccines.
So, when should they use the ENS? Well, I don't think the current swine flu will get to this point, but if it should reach epidemic proportions, we want to isolate large parts of the population, and we choose to do that with large isolation camps, then we should actively notify the public. Shy of that, though, we should inform the population as much as they want to hear.
And if we want to offload the burden on our 9-1-1 call centers and government health departments, we should do that with a well advertised H1N1 Hotline.