LONDON, ENGLAND - MAY 04:  Facebook lights up the London Eye with the nation's general election conversations. Last night the London Eye showed the top five most discussed political topics on Facebook. (Colours: Economy - white; Health - purple; Tax - yellow; Europe and Immigration - blue; Crime - red) on May 4, 2015 in London, England.  (Photo by Tim P. Whitby/Getty Images for Facebook UK)