I think he's suffering from a Cornish view of London. The chances of being hurt by a terrorist in the capital are miles lower than twisting your ankle on Bodmin Moor!
I'm NOT going to respond in kind.
It's fact that there are millions and millions of people, young and old, out and about in London, Birmingham, Manchester and Glasgow right now. You've suggested they're cowed. They aren't. It's demonstrable.
As for "twat", every time you say something that turns out to be plain wrong you either flounce or get crudely abusive. It's a pattern.