Professor Cole, unlike many of these people, has actually spent time in Second Life, and considered how usable it would be as a breeding ground and training ground for terrorists. His conclusion is stated in political terms, but can be summed up as it's a paranoid fantasy, a tool of FUD to try and get internet monitoring pushed through the legislation despite it being unconstitutional. Most people I know consider the use of SL for education and training in many skills as excellent, but by and large regard it as a poor place for teaching "physical" skills (sports for example, and bomb building and assaults on buildings). They tend to regard the prospect of training terrorists in Second Life as risible. However, these people do read a lot, and they managed to include a link to the original discussion document that has spawned many of these more and more paranoid stories.