A terrorist alert that instills a vague feeling of dread or panic, without giving people anything to do in response, is ineffective. Even worse, it echoes the very tactics of the terrorists. There are two basic ways to terrorize people. The first is to do something spectacularly horrible, like flying airplanes into skyscrapers and killing thousands of people. The second is to keep people living in fear. Decades ago, that was one of the IRA's major aims. Inadvertently, the DHS is achieving the same thing.Link (Thanks, Bruce!)
European countries that have been dealing with terrorism for decades, like the United Kingdom, Ireland, France, Italy, and Spain, don't have cute color-coded terror alert systems. Even Israel, which has seen more terrorism -- and more suicide bombers -- than anyone else, doesn't issue vague warnings about every possible terrorist threat.