Filed under: TransportationHey, we try our best to be as paranoid as the next guy, but we confess we were caught a little off guard by this one. US Department of Homeland Security folks announced yesterday that three American Airline passenger planes that frequent JFK airport are going to be set up with anti-missile systems in a test run to see if they'd be effective in helping to prevent a terrorist shooting down a jet with a shoulder-fired missile. It's step three in a government-mandated program to determine the suitability of such systems, which involve radar