Visitors of the world's longest tree top walk between the trees of the Bavarian forest on November 6, 2009 in Neuschoenau, Germany. The path, 1300 meters long and in 8 to 25m height, winds up to an impressive tower with a height of 44 meters. The wooden construction is integrated into the forest and delivers a natural experience. (Photo by Miguel Villagran/Getty Images)

An activist in a Guy Fawkes mask adjusts a skull and crossbones flag during a demonstration against the Anti-Counterfeiting Trade Agreement (ACTA) on February 25, 2012 in Berlin, Germany. (Photo by Adam Berry/Getty Images)

A student runs for cover as riot police clash with students during a demonstration on February 29, 2012 in Barcelona, Spain. Student associations have called upon 120,000 students to strike in protest against education cuts recently announced by the Catalan government. (Photo by David Ramos/Getty Images)

Ultra orthodox children stick their tongues out as snow falls on March 2, 2012 in Jerusalem, Israel. This is the first time in four years that the Israeli captial has experienced snow fall. (Photo by Uriel Sinai/Getty Images)

The Queen Mary 2 is saluted by the HMB Endeavour, the replica of Captain James Cook's ship, on March 4, 2012 off the coast of Victoria, Australia. (Photo by James Morgan/Carnival Australia via Getty Images)

Kat Von D attends her first solo art show “New American Beauty” at Sephora Antara store on March 1, 2012 in Mexico City, Mexico. (Photo by Victor Chavez/Getty Images For Sephora)

Natalie Burgener drops the bar behind her head while attempting to snatch 98 kilograms during the 2012 U.S. Olympic Team Trials for Women's Weightlifting on March 4, 2012 in Columbus, Ohio. (Photo by Jamie Sabau/Getty Images)

Actor Danny DeVito attends the “Dr. Seuss' The Lorax” (Der Lorax) Germany Photocall at Ritz Carlton on March 5, 2012 in Berlin, Germany. (Photo by Andreas Rentz/Getty Images)