But only a baby step.
Howard Melamed, who runs a signal amplification company called CellAntennna, says mobile telephones have a lot of features that make them attractive to would-be bombers. Making them unable to send or receive calls helps, but it doesn't disable the precise timers, or make the batteries themselves less explosive.
Melamed admits if they couldn't use cell phones, "Terrorists would find some way to attack us."
But he adds: "Let's not make it so easy."
Cell phone service was later restored in the Brooklyn-Battery and Queens-Midtown tunnels after the original move by authorities to pull the plug on cell phone service in the four tunnels into and out of Manhattan in response to terrorist bombings in London.
The transmitters that provide wireless service in the Holland and Lincoln tunnels are still off.
Cell phones have been fashioned into detonation devices in bombings in Madrid and elsewhere. But when cell service is cut in tunnels, drivers can't dial 911.
That led some authorities to question the decision to stop phone service. New York City Mayor Michael Bloomberg admitted that "cell phones provide a measure of comfort."
Investigators in London have said they believe the four bombs there were set off with timing devices, but they haven't determined what kind.
London's bombings killed more than 52 people and injured more than 700 others.
The Port Authority of New York and New Jersey, which runs area transit hubs, bridges and tunnels, decided last Thursday to indefinitely sever power to transmitters providing wireless service in the Holland and Lincoln tunnels, spokesman Tony Ciavolella said Monday.
The Metropolitan Transportation Authority, which controls the nation's largest mass transit system, also suspended mobile phone service in the Brooklyn-Battery and Queens Midtown tunnels after the London attack, but it reinstated service Monday afternoon.
The MTA initially said the service had been shut off at the request of police but later issued a statement saying there had been a miscommunication been the two agencies; an MTA spokesman declined to elaborate.
Police said they didn't request cell service be shut off.
The Department of Homeland Security said the decision in New York to cut off cellular service was made without any recommendation by the federal government's National Communications System, which ensures communications are available during national emergencies.