Putin foe

For 20 years Garry Kasparov was the greatest chess player in the world. He won his first world championship at the age of 22 and was ranked number one almost continuously until he retired from international competition two years ago, a Russian hero and a very wealthy man. He could have done anything he wanted. Instead, he chose to make the riskiest move of his career: he entered the treacherous world of Russian politics, and has become one of President Vladimir Putin's harshest critics, accusing him of abolishing democratic reforms, and turning over the country's vast natural resources to a small political elite. (more on CBS)