it s all about porous borders. if you want to jump on the euro star you have to go through airport type checks, show your passport, go through scanners to get on the train at kings cross and into paris. if the you want to go from paris to south of france or paris to amsterdam or paris to anywhere outside of france but in the contains of the european union it s pretty easy. you jump on a train and you go from a to b. and it s virtually impossible, i would say, for security forces to be able to monitor every single person going on those trains. it s logistically impossible to set up security type checks for train checks of people traveling across europe. that s the problem we ve got and it s incumbent on all of us, whether it s in a small way, through eyes and ears listening, reporting, picking up the phone if you see something odd, all the way through to what these two chaps did and actually getting involved and assaulting someone to prevent a catastrophe. it s a broad spectrum.