It's kind of funny because I was quite involved in the 2010 Olympics, and there was a risk and threat assessment done by the RCMP and CSIS. They actually identified that the worst threat was a transport of propane or a fuel tank. That was more dangerous than a nuclear threat, so I think it's there and it needs to be looked at, but I wouldn't say that it's the highest threat right now.
On February 11th, 2013. See this statement in context.