Encyclopedia Britannica editions are seen at the New York Public Library on March 14, 2012 in New York City. Encyclopedia Britannica announced it will be ceasing its print edition of reference books for the first time in its 244-year history to focus solely on digital versions. (Photo by Mario Tama/Getty Images)

Members of the American Civil War Society take part in a mock battle in the grounds of Cusworth Hall, South Yorkshire on July 2, 2011 in Doncaster, United Kingdom. Enthusiasts from all walks of life are taking part in re-enacting scenes from the American Civil War and in 'living history' events which are as authentic as possible. (Photo by Christopher Furlong/Getty Images)

Museum employee Victoria views a giant grouper fish specimen at the Natural History Museum in west London March 25, 2015. It forms part of a new exhibition, “Coral Reefs: Secret Cities of the Sea”, featuring a panoramic virtual dive and over 250 specimens from the Museum's coral, fish and marine invertebrate collection, which opens on March 27. (Photo by Toby Melville/Reuters)

An Ambassador car, licensed as taxi rolls past other vehicles through a busy road in Kolkata, india, Monday, May 26, 2014. India's oldest car factory has abruptly suspended production of the hulking Ambassador sedan that has a nearly seven-decade history as the car of the Indian elite. (Photo by Bikas Das/AP Photo)

#1: Superman. According to McAfee, 16.50% of Web searches for Superman led to sites with viruses and other malicious software. Pictured here: The Superman costume that was worn by Christopher Reeve in “Superman: The Movie” on display at Profiles In History in Calabasas, northwest of downtown Los Angeles, on July 19, 2012 in California. (Photo by Frederic J. Brown/AFP Photo)

A rider on horseback competes in the Margalla Festival Tent Pegging Championship in Islamabad, Pakistan, June 5, 2016. Tent pegging is an equestrian sport popular in India and Pakistan, with a history going back to the cavalries of ancient armies. (Photo by Caren Firouz/Reuters)