Meet a man who built a barbecue smoker out of a file cabinet

Is it real? Does it work? Is it safe? Was it hard to make? Why would anyone build one? Why is he selling it and trying to get a broken chainsaw in return? And, is this a singular piece of American ingenuity or is there an underground community of file cabinet smokers that I had never heard of before now? The seller, and an expert, tell us everything.