Igor Perne (L), 53, an electronic engineer and a member of the International Virtual Aviation Organisation (IVAO), and fellow virtual pilot Franc Lavric gesture for the camera before taking off on a virtual flight in a flight simulator in Nova Vas, Slovenia November 13, 2014. In 2011, Perne, a lifelong flying enthusiast, bought parts of a written-off Cyprus Airways airliner and then spent two and a half years turning the entire nose of the scrapped aircraft into an elaborate flight simulator. (Photo by Srdjan Zivulovic/Reuters)

A protester clashes with a police officer in Athens' central Syntagma (Constitution) Square in this June 15, 2011 file photo. Greece triggered the regional financial crisis in 2009 when a far higher budget deficit than previously calculated emerged. The collapse of talks with creditors in Paris last November set off a month-long sequence of events leading to elections this week and proving Greece is still the region's weak link. The vote is expected to be won by Syriza, a far-left party opposed to the bailout, worrying investors and creditors alike. (Photo by Yannis Behrakis/Reuters)

An Israeli tank moves into position in the Israeli controlled Golan Heights during fighting between forces loyal to Syrian President Bashar Assad and rebels in the Druze village of Khader in Syria, Tuesday, June 16, 2015. As many as 20 members of the Druze minority sect were killed last week, the deadliest violence against the Druze since Syria's conflict started in March 2011, sparking fears of a massacre against the sect. (AP Photo/Ariel Schalit)

Protesters dressed as cows march during a demonstration outside of the Wisconsin State Capitol on March 12, 2011 in Madison, Wisconsin. Tens of thousands of protestors staged a massive demonstration outside of the Wisconsin State Capitol one day after Gov. Scott Walker signed his controversial budget repair bill into law.

A clock showing a countdown to the start of the London 2012 Olympics is unveiled on March 14, 2011 in London, England. The clock is starting five hours from midnight when 6.6 million tickets for the Olympics will become available and 500 days before the Games start. There is a six-week window to apply for tickets on the London 2012 website.

A performer plays the role of the Emperor during a re-enactment of an ancient ceremony of Qing Dynasty Emperors praying at Ritan Park which holds the ceremony of 'fete day'' to mark the first day of spring on March 21st, 2011 in Beijing, China. March 21st is the Day of Vernal Equinox according to the Chinese lunar calender. (Photo by Lintao Zhang/Getty Images)

A sheep and a gentleman farmer take to the streets of London today to mark the launch the new English Countryside chapter of Farmville, Zynga's global social gaming phenomenon on March 29, 2011 in London, England. Farmville English Countryside gives players all-new crops, buildings and decorations located in the beautiful English Countryside. (Photo by Gareth Cattermole/Getty Images for Farmville)

Prince Philippe and Princess Letizia of Spain meet with Israeli president Shimon Peres at the presidential residence on April 11, 2011 in Jerusalem, Israel. The Spanish Royal couple is on their first official visit to Israel together. The Prince's parents, the King and Queen of Spain last visited in 1993.