That's reducing things to a logical extreme and removing all considerations of practicality. In the end, that's not a good way to look at law, or the nitty-gritty of the world for that matter. If you find someone with nude photos of yourself, and you didn't give them to them, then you can conclude that those photos were obtained illegally. That fixation on the distinction between "technically just posession" and "creation/distribution/etc." is not really helpful.