What this highlights is just how odd the idea of 'suspicious items' is, in an environment where just about everybody has a bag or suitcase and all have immediate, unchecked access to trains. If you really wished to leave a device on a train, you'd just put it in the luggage rack, in a plain bag just like everyone else's. The industry must of course follow the government instructions, but as ever it is the intelligence agencies who are really fighting the battle here, long before any dodgy ingredients make it as far as a railway station.
This is presumably why terrorists shifted their tactics to weapons, and have shifted again from firearms to more easily obtainable items, as seen with the knife and axe attacks recently on European trains. Indeed, I wonder how long before it is decided to remove the usual axe, crowbar etc from publically-accessible emergency cabinets on UK trains.
