[Canard]

""victims who defend themselves against an attacker can be jailed for defending themselves."

Is this really true or is it an urban legend?

It seems hard to believe that if someone comes after you with a knife that you could be in trouble for fighting back."

It's certainly an exageration. If you fought back against an attacker and, at some point, a jury decided that the force you used was disproportionate, then you could be found guilty of a crime. This is the guidelines used by the Criminal Prosecution Service if considering a prosecution:

http://www.cps.gov.uk/legal/section13/chapter_t.html

"t is important to ensure that all those acting reasonably and in good faith to defend themselves, their family, their property or in the prevention of crime or the apprehension of offenders are not prosecuted for such action."

[webstersII]

"If you fought back against an attacker and, at some point, a jury decided that the force you used was disproportionate, then you could be found guilty of a crime."

Thanks for the clarification.

That sounds similar to the law in many states in the U.S. You can only use reasonable force against an attacker, i.e., you can't kill someone just because they take a swing at you. If they pull a deadly weapon on you then that's a different case and you can respond with deadly force.

Also, many states make the inside of your home a special case and will not prosecute for just about anything that you do to an intruder. But there are a number of states which require you to use no more force than necessary even in your home, and if you have the chance to retreat from the attacker then you are obligated to do so.