The obvious retort is that having it on a hard drive isn't the crime, the act of collecting it is. So it's the act and not the possession that is the crime. I

The obvious retort is that having it on a hard drive isn't the crime, the act of collecting it is. So it's the act and not the possession that is the crime. I would note as a counter-counter argument that we often make things illegal that are not in themselves harmful, but can lead to harm.