A world without Ducati 916s is a world in which Mick and I would not want to live. Or a world without Ferraris and Corvettes. Their entire charm exists on the far side of the speed limit, and yet they are legally built, bought and used. We are free, for the most part, in our society to have things that can or might be put to illegal use, so long as we keep our behavior within the law. Even beyond the law, it is the act and the actor that are proscribed, not the inanimate object used in the act.
Some people ride fast motorcycles fast.
But all riders, fast or not, imagine themselves scorching through the corners with their knees skimming the pavement, raising a fist in victory as the checkered flag falls. We all have fantasy lives and we enjoy them. Fantasy is a relief from dull reality, and the richer the fantasy the easier it is to endure reality without having to act out unacceptable behavior in public. We call it catharsis and know it to be a healthy release. Couples who can play at their little sexual fantasies in privacy and mutual consent tend not to run around tying people up and raping them.