FILE - In this Thursday, June 6, 2013, file photo, pedestrians use their cell phones as they pass a Verizon Wireless store near Union Square, in New York. Verizon Communications announced Wednesday, Sept 11, 2013, it has sold $49 billion in bonds, the largest corporate bond sale in history. (AP Photo/John Minchillo, File)
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Cell phones sit on display in the window of a store on January 14, 2013 in New York City.
Audience members hold their cell phones high as President Barack Obama speaks during a Cinco de Mayo reception in the East Room of the White House in Washington, on May 5, 2015.
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Cell phones on campus
ANN STATES FOR TIME
Cell phones are constant companions for Atlanta teenager Royce Badger, right, and friends
Cancer not calling: Cell phones have received a provisional clean bill of health
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A man and a woman speak on cell phones near a telephone booth in London, U.K., Wednesday, October 18, 2006.
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Sen. Rand Paul holds up a group of cell phones in front of U.S. District Court to announce the filing of a class action lawsuit against the administration of U.S. President Barack Obama, Feb. 12. 2014.
Rich Pedroncelli / AP
Correctional Officer Jose Sandoval inspects one of the more than 2,000 cell phones confiscated from inmates at Calfornia State Prison in Vacaville, California.
Julio Cortez / AP
Officials secure an area in Watertown, Mass., Friday, April 19, 2013. There were reports of explosives being detonated and police telling reporters to turn off their cell phones.