I don't know if this has been news in the US, but last week I read an article in my newspaper about a KLM airplane being denied access of US airspace, which had to return to Schiphol while it was already flying over Canada. The reason was two passenger which were on the US no-fly list. KLM did not give the passenger list to US authorities, since no landing was planned. Apparently Mexican authorities (the destination of the airplane) warned the US. Today I see there is an article in NewsWeek covering the incidence. Apparently the passengers took flight lessons at the same airschool where the 9/11 hijackers took flight lessons. Mystery Flight - Two passengers trigger alarms—and fresh echoes of 9/11.