Here in the USA by law if you're attacked you're allowed to defend yourself. However there are certain conditions that must be met in order for your actions to be considered "self defense" by law. For one thing obviously you have to be attacked. Also, you can't continue to beat on an assailant after you've stopped them. Lets say an attacker is coming at you, you knock them out with a punch and as they're laying there unconscious you proceed to kick and stomp them. At that point it is not self defense as you've stopped them and they're no longer a threat. Both those things I mentioned above I think are good guidelines. However what I do disagree with is having to respond with force on force. Having to use a level of force that is in proportion to the level of force your attacker is using. This is just an idea but my proposal is to get rid of that standard. Another words, to make it so that there is no limit to the level of force you can use against an attacker as long as you stop when the attacker stops. This is just a thought and if anybody disagrees they are welcome to state their opinion and as to why.