No they don't. I have a few friends that live in Denver (or Englewood, Lakewood, Denver, and I live in Summit County) that have there cards. I am a caregiver, and my friends are all card holders. None of us have ever had a issue. As long as you are respecting the law you should have no problems. By the way I just started a Colorado Medical Marijuana Group to talk about everything that is going on in our state.