The CBRE Urban Photographer of the Year competition – now in its ninth year – encourages professional and amateur photographers to capture cities at work. Here: Dog Walker – 15:00. The competition allows photographers to enter up to 24 images, one representing each hour of the day. (Photo by Johanna Siegmann)

A participant poses with his laptop during the 33rd Chaos Communication Congress on its opening day on December 27, 2016 in Hamburg, Germany. The annual event is bringing together 12,000 computer hackers and activists who will meet over the next four days to share expertise and discuss topics related to the society and the digital world. (Photo by Morris MacMatzen/Getty Images)

A child wearing a costume runs up the steps during Purim celebrations at the Coral Temple synagogue in Bucharest, Romania, Wednesday, March 20, 2019. Children put on fancy costume dress joining dozens of believers from Romania's Jewish community who attended a Purim service to celebrate the Jews' salvation from genocide in ancient Persia, as recounted in the Book of Esther. (Photo by Vadim Ghirda/AP Photo)

A demonstration on March 15, 1922 on Palace Roof, 57th Street and 7th Avenue, showing the shellproof steel jacket. Leo Krause wearing the jacket, which weighs 12 pounds. Shots used, 38 and 45 calibre, at close range. (Photo by Bettmann Archive)

Ana Ivanovic of Serbia plays a backhand return to Maria Sharapova of Russia during their women's singles final match at the Brisbane International tennis tournament in Brisbane, January 10, 2015. (Photo by Jason Reed/Reuters)

An aircraft passes over houses at it lands at Heathrow Airport near London, Britain, December 11, 2015. Picture taken December 11, 2015. (Photo by Neil Hall/Reuters)

A Malaysian Royal Guard wears a protective mask while he stands guard outside National Palace, following the outbreak of a new coronavirus in China, in Kuala Lumpur, Malaysia, February 10, 2020. (Photo by Lim Huey Teng/Reuters)

Cars slowly move along a bridge in traffic jam in central Moscow, Russia on December 11, 2018. (Photo by Yuri Kadobnov/AFP Photo)