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Atenção: A questão refere-se ao texto abaixo.

    Subway and local train systems pose many of the same obstacles as airports for security professionals. Their efficacy relies on efficiency: People want to be able to get in and out as quickly as possible. But in both Delhi and Mumbai, subway lines often stretch out of the stations, as people patiently wait to put their bags through an X-ray machine and walk through a metal detector. Do citizens accept it because it’s always been that way? Or is the memory of the 2006 and 2008 attacks in Mumbai fresh enough that they are willing to take on the inconvenience, as long as it translates to safety? Programs like Global Entry and TSA PreCheck in the U.S. have been employed to increase the number of "known travelers" (and speed up the process when security risks are low), but recent news of a flight attendant who was part of TSA's Known Crewmember program − found with 70 pounds of cocaine in her carry-on − shows that no system is flawless.

    Subways hold mass appeal because of their convenience, and it seems unlikely that the Delhi model could be replicated in other large public transit systems. Delhi has a daily ridership of about 2.3 million passengers, and the X-ray machines and metal detectors already act as a bottleneck to service. (New York, by comparison, has a daily ridership of about 6 million.) "Airport-style security in a train station or metro would be extremely cumbersome, given the much larger number of passengers using metro systems on a daily basis," says Matthew Finn, a London-based security specialist. Instead, he sees a different approach as a solution to metro security: "There are roles for other security layers, such as explosive detection canine units, real-time video analysis, behavioral analysis, and passive explosive trace detection systems."

(Adapted from http://www.cntraveler.com/stories/2016-03-25/brussels-attacks-expose-global-weaknesses-in-airport-subway-security)