In making public-policy arguments, analogies are dangerous. You need to take time to explain them. The opposition can use other analogies. It's far more effective to argue on the facts. With respect to encryption, the outgoing administration has argued successfully that encryption is the computer equivalent of a saturday night special. That there is no reason to use encryption unless you don't want law enforcement to be able to read what you send. They say that it is only useful against lawful wiretaps, because there are other protections against unlawful wiretaps (ie: the law). The way to attack this is not by making an analogy to photocopiers, but by saying that there are many unlawful wiretaps, breakins, and thefts, and that most of them go unknown and unreported. Argue that most communications that people have an interest in protecting are not about kidnappings but about business dealings. Argue that encryption is vital for communicating with overseas offices, where wiretaps are even more common. Argue that it is important for protecting information on your hard disk which can be stolen. No need to argue with analogy.