Yes. Cat Stevens, aka Usef Islam, has been denied entry into the United States because he is considered a security threat. This should show you how fucking stupid our nation has become. IF it doesn't then you're one of the dumb ones.
http://story.news.yahoo.com/news?tmpl=story2&u=/ap/20040922/ap_on_re_us/plane_diverted
http://story.news.yahoo.com/news?tmpl=story2&u=/ap/20040922/ap_on_re_us/plane_diverted