Two attendees compete in the biggest vape cloud competition at the Vape Summit 3 in Las Vegas, Nevada May 2, 2015. According to new research provided to Reuters, youngsters say that performing tricks is one of the top two reasons they began using e-cigs. (Photo by David Becker/Reuters)

Robert Price of TREWGrip LLC demonstrates a TREWGrip handheld rear-type keyboard and air mouse for Apple and Android tablets at the “CES: Unveiled”, media preview for International CES, at the Mandalay Bay Convention Center in Las Vegas on January 5, 2014. (Photo by Robyn Beck/AFP Photo)

Miss USA 2012 Nana Meriwether crowns Miss Connecticut USA Erin Brady the new Miss USA during the 2013 Miss USA pageant at PH Live at Planet Hollywood Resort & Casino on June 16, 2013 in Las Vegas, Nevada. (Photo by Ethan Miller)

Competitors in the Pro Bikini division pose during the Arnold Classic Australia at The Melbourne Convention and Exhibition Centre on March 14, 2015 in Melbourne, Australia. (Photo by Robert Cianflone/Getty Images)

Activists dismantle Ukraine's biggest monument to Lenin at a pro-Ukrainian rally in the central square of the eastern city of Kharkiv, Ukraine, Sunday, September 28, 2014. (Photo by Igor Chekachkov/AP Photo)

A pro-independence protester sits in front of Catalonia's regional parliament as lawmakers vote inside, in Barcelona, January 16, 2014. (Photo by Albert Gea/Reuters)

Pro-government fighters stand next to a tank destroyed during recent fighting in Yemen's southwestern city of Taiz March 14, 2016. (Photo by Anees Mahyoub/Reuters)

A pro-abortion activist wearing a poncho with an illustration of a woman in jail, demonstrates to demand the decriminalization of abortion in Mexico City, Mexico September 28, 2016. (Photo by Carlos Jasso/Reuters)