I thought Mayor Bloomberg of New York City spoke very clearly on the subject today. He said these various color coded levels of threat are directed at the security forces across the country, not members of the public. That's the only part of it that has started to make sense to me.

And, no. I don't think that more threat necessarily comes from "strange looking guys". Reminds me of an argument I had years ago with someone who said that I'd feel differently about it someday when I was "faced with a black guy pointing a gun" at me. I told him I'd feel every bit as bad about it if it was a white guy.