I find this interesting as it stands beside a post wherein a government-level prosecutor said they wouldn't charge folks for stabbing B&E criminals. Something involving a granny.
I suppose it's ok, as she couldn't be expected to overpower her intruder...
Knives are deadly, folks, and all manner of knives abound throughout the criminal world, even in London. A person armed with a knife can kill you in 1 second from 20 feet away, even if you never see the knife.
That's why I carry a gun. It has better range.