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)

An altar is pictured after it was decorated by the Antar family with some 3,000 traditional cheese and corn buns called “chipas”, in celebration of Kurusu Ara in Asuncion May 3, 2015. Kurusu Ara, the Day of the Cross, is a Catholic festival that is combined with local Gurani culture and falls annually on May 3. Paraguayans typically celebrate the festival with chipas, used to decorate religious shrines and altars. The chipas are later distributed to attendees. The buns at the top are arranged to read, “March 3 live”. (Photo by Jorge Adorno/Reuters)

A man smokes marijuana during a demonstration in support of the legalization of marijuana in Medellin, May 2, 2015. (Photo by Fredy Builes/Reuters)

Fighters from Germany take up position before competing in the Medieval Combat World Championship at Malbork Castle, northern Poland, April 30, 2015. Medieval combat is a full contact sport that revives the foot based tournament fighting of medieval Europe. Countries fight in refereed matches where the objective is to get the opposing team to the floor. There are also duels with polearms, swords and shields where the number of hits landed are scored. The fighters, both male and female, wear heavy armours and weapons, mostly replicas of authentic pieces, and fight following the knights code of conduct. According to organizers, 25 nations from 6 continents are taking part in the Championships, which started on April 30 and will go on until May 3. (Photo by Kacper Pempel/Reuters)

In this picture taken on Saturday, January 31, 2015, Zohreh Etezadossaltaneh, center, talks on her mobile phone, held with her foot, during a meeting at her friend's home in Tehran, Iran. Now 52 years old, the retired Iranian teacher who was born without arms has dedicated herself to helping others with similar disabilities live full and satisfying lives. (Photo by Ebrahim Noroozi/AP Photo)

Rene Penia drives his VW Beetle 1995, locally called “Vocho”, through the streets of Monterrey April 22, 2015. The car was painted by a local artist to be part of an exhibition on the 1960s at the National History Museum in Monterrey where it was on display for five years. Pena bought the car for 25.000 Mexican Pesos (some USD 2,000 at that time) in 2013 during an auction and he then converted the car into an electrical vehicle. (Photo by Daniel Becerril/Reuters)

Revelers take a selfie during a Holi Festival in Madrid, Spain, Sunday, April 26, 2015. The festival is based on the Hindu spring festival Holi, also known as the festival of colours where participants colour each other with dry powder and coloured water. (Photo by Andres Kudacki/AP Photo)