Surfer Arlen Macpherson sits on his board, which has an electronic shark repellent device installed, at Sydney's Bondi Beach in Australia, August 18, 2015. A spate of shark attacks in Australia has left some of world's top surfing beaches deserted and many people having second thoughts about taking a swim as the summer approaches. Macpherson paid A$390 for a device embedded in his surf board to repel sharks by emitting an electronic force field that overpowers its sensing organs. (Photo by David Gray/Reuters)

Andrey Karr from Western Riders Slacklines at sunset above big waves in Nazare, Portugal on December 27, 2017. (Photo by Aidan Williams/National Geographic Travel Photographer of the Year Contest)

Fashionistas pose for photographs in front of a homeless man outside Moynihan Station following a showing of the Rag & Bone Spring/Summer 2013 collection during New York Fashion Week in this September 7, 2012 file photo. (Photo by Lucas Jackson/Reuters)

In a January 19, 2014 photo Phillip Seymour Hoffman poses for a portrait at The Collective and Gibson Lounge Powered by CEG, during the Sundance Film Festival in Park City, Utah. Hoffman, who won the Oscar for best actor in 2006 for his portrayal of writer Truman Capote in “Capote” was found dead Sunday in his apartment in New York with what law enforcement officials said was a syringe in his arm. He was 46. (Photo by Victoria Will/AP Photo/Invision)

A woman walks up the steps decorated ahead of the Chinese New Year festival in Beijing, China, Thursday, January 12, 2017. The Chinese Lunar New Year is the most important holiday for Chinese and hundreds of millions are expected to return to their hometown to spend the new year with their family and relatives. (Photo by Ng Han Guan/AP Photo)

A Thai traffic security guard wears a Santa Claus costume as he directs the traffic on a street during Christmas celebrations outside a shopping mall in Bangkok, Thailand, 22 December 2015. The campaign of a shopping mall is held to celebrate the upcoming Christmas season and to attract shoppers. (Photo by Narong Sangnak/EPA)

In this October 21, 2015, file photo, a young man rides a hoverboard along a Manhattan street toward the Empire State Building in New York. More than 500,000 hoverboards are being recalled after reports that they can burst into flames. The Consumer Product Safety Commission said Wednesday, July 6, 2016, it has received 99 reports of battery packs in the two-wheel motorized scooters catching fire or exploding that causing burns or property damage. The recalled hoverboards were made by eight companies. (Photo by Kathy Willens/AP Photo)

Reem Fawzy (L), the director of the Pink Taxi company, stands with her drivers in a parking lot in Cairo, Egypt, September 6, 2015. Pink uniforms, a pink logo on the cars, and even pink nail polish – it's all part of the look of women-drivers working for Egypt's first women-only taxi service. The Pink Taxi company hires only women drivers and gives rides to only female passengers. The company was started in an effort to provide a safe taxi service for women in a country with high rates of sexual harassment, said Reem Fawzy, the director of the company. (Photo by Amr Abdallah Dalsh/Reuters)