In some jurisdictions in the United States possession of prescription drugs in a pill organizer is a crime, and people have been prosecuted for it. The legal theory is that since the drug is not in the package it was dispensed in by the pharmacy, and since it is not "in use" (e.g., swallowed), it is unlawfully possessed. The affirmative defense, which is that you do in fact have a valid prescription for the drug in question, is not always accepted by the court.