Well of course the cyber-attackers would hack into the system and make it so the passenger train made a stop at the lethal chemicals plant to attach a tanker, and THEN derailed it. All with cyber attacks. Cyberly.
Anyone who buys a knife should be required to do mandatory time in jail because they are capable of murder. It doesn't matter if you intended to use it for such a purpose, but the fact that it is capable of murder and is frequently involved in murder is reason enough for you to pay for it.