The contentious issue is the use of 'excessive' force if defending yourself.
However, if someone tries to have it away with my DVD collection or anything else for that matter (which I've worked hard to pay for) after having smashed in my back door, then I regard no force as excessive enough in stopping them, because they bloody well asked for anything they got. And if I was on a Jury for a case such as this, I'd recommend giving the homeowner a medal, not a fine or custodial sentence.
The law is indeed 'an ass' a lot of the time.
Chock