Tenement apartments at a Roma Gypsy Housing Estate In Plovdiv, Bulgaria

Arab using two-way radio to communicate during parade of armed forces in Abu Dhabi, United Arab Emirates

Combined heat and power station Berlin Buch, Vattenfall, control of the chimney

Redhead woman in studio photography online payment with mobile on a blue background

Redhead woman in studio photography online payment with mobile on a purple background

Urban Lifestyle. A group of people, men and women on a city bus, in New York city. A couple side by side looking at a digital tablet, New York city, USA

People outdoors in the city in spring time. New York City park. A young woman holding out a phone to take a photograph of herself and a companion, New York City, USA

New York city. The Brooklyn Bridge crossing over the East River. A couple taking a picture with a phone, a selfy of themselves, New York city, USA

Urban lifestyle. Two young men using their phones to take images of the city from an observation platform overlooking the Empire State Building, New York city, USA

City life in spring. Young people outdoors in a city park. A couple taking a self portrait or selfy with a smart phone, New York city, USA

A couple, a man and woman taking a selfy with a smart phone.

New York city. The Brooklyn Bridge crossing over the East River. A couple taking a picture with a phone, a selfy of themselves, New York city, USA

City life in spring. Young people outdoors in a city park. A man checking his cell phone. Four people under a tree in blossom, New York city, USA

New York City. An observation deck overlooking the Empire State Building. A woman using her smart phone to take a photograph of herself and the view over the city, New York city, USA

People outdoors in the city in spring time. New York City park. Two women in a group of friends, looking at a cell phone and smiling, New York city, USA

A small group of people, a businesswoman and two businessmen outdoors in the city.

New York city, the Brooklyn Bridge crossing over the East River. Three women in a row, smiling, as one takes a picture with a smart phone, New York city, USA

City life in spring. Young people outdoors in a city park. A young woman and man sitting side by side looking down at a smart phone, New York city, USA

A man in a city at night, looking at a computer tablet, New York city, USA