Smallest Minority has a post listing something of the problems in Britain with defending yourself in your own home.
Basically, under their law you can use 'reasonable force', but there's no standard for it. And if you act in self-defense, and even for a moment intend to cause serious bodily harm, you're screwed. That makes you a criminal, and if the bad guy dies you go to jail for life.
Think about that. If someone attacks you in your home, and you fight back, OF COURSE you intend them harm! You're scared, you're mad, you're trying to protect your home and yourself, and this is why defending yourself in Britain makes you as or more likely to go to jail than the criminal is, at least for a long length of time. Which is insane. And if you're out in the street and defend yourself from attack, my understanding is that it's even worse.
A while back someone wrote, "Stick a fork in Britain, they're done", and if this doesn't change drastically, he's right. When you are not allowed, by your own government, to protect yourself from attack by any means necessary, not even in your own home, you're not a free citazen any more. You're a good halfway to being a slave.