In the wake of the Madrid bombings, rail security has been increased in Europe, the U.S., and Australia. Such measures as increased police patrols, more bomb-sniffing dogs, and additional electronic surveillance equipment are typical responses, but it is hard to imagine how a determined terrorist could be stopped from attacking a train. European officials are reluctant to adopt the same kinds of security checks common in the airline industry. Unless such policies are accepted and implemented, trains are likely to remain vulnerable.