Under UK law it is certainly illegal to create any device with the intention of causing greivous bodily harm to anyone. The right to self defense is very precisely that, the right to take reasonable steps to defend yourself with commensurate force if attacked. If someone hits you in the face you do not have the right to kill him. If someone tries to do serious harm to you and the only way to avoid that harm is to kill them that is self defense. There is no self defense argument where the purpose is not to prevent physical harm. Any device intended to cause harm to someone tampering with a computer could well land the perpetrator in jail for a very long time for attempted murder or murder. People who go round drawing parallels to gun ownership and cryptography ownership are simply playing into the governments hands. Cryptography has net benefits to society. Most advocates of gun ownership tend to convince me of little more than they are a danger to society. Regardless of their case they are the biggest argument for gun control, and therfore poor advocates of their cause. I see their attempts to draw parallels with cryptography to be little more than trying to shore up their sinking ship with one thats afloat. Phill