Homeland Security Warnings: Designing emotions
This is how it looks the present US´s Homeland Security Warning:
And this is one of the proposals given by a group of designers:
In a country where everything is covered by danger and warnings I think this second approach is a smooth way of warning travellers. I simply love the buttons «Tell someone» / «Take action» in the «Be alert» mode.
More proposals at the NYT: Better Signs of Trouble