What will Sochi do for Olympic brand?

The final countdown to the Winter Olympics in the Russian resort of Sochi has been hit by controversy - from reports of unfinished hotels to security fears. Now the United States has warned airports and some airlines flying to Russia over possible bomb ingredients in toothpaste tubes. It's the latest headache for the Games' organisers, and Joanna Partridge asks if the stories out of Sochi could hurt the Olympic brand.