Mr Ling, whose job includes loitering in public places for observation, watched a woman at an Oslo underground station who texted as she walked.

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It also has an underground retail and restaurant area where direct access to the Otemachi subway station will open in 2013.

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Robin Moulna, 38, a manager at a fast-food restaurant, was surprised to receive a call from his brother while waiting for an F train in the Rockefeller Center subway station, two levels underground.

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