By Alan Baldwin LONDON (Reuters) - Olympic champions Mo Farah, Rafael Nadal and Justin Rose were among athletes targeted on Monday in the latest leak of confidential medical documents that the world anti-doping agency (WADA) says were hacked by a Russian cyber espionage group. Britain's Farah became only the second man to retain the 5,000 and 10,000 metres Olympic titles at the Rio de Janeiro Games last month while compatriot Rose won the first gold medal in golf for 112 years. Spaniard Nadal, a 14-times tennis grand slam winner, won Olympic men's doubles gold with Marc Lopez. More...