That's from his book, which is also a great read.
His title is interesting because things like this - fearmongering hyperbole of the worst kind - detracts from the actual threat. When fraudulent garbage like this is exposed people might think "hey, what else isn't true?"
There is a very real threat, but it sure as hell isn't from suitcase nukes.
I don't think I would own any guns if I had to clean them every six weeks despite never shooting them.