That is a bit of a gray area. I would not deal with anyone that is a convicted felon but you may not be able to find that out without checking his ID at the sheriffs office. Legally there might not be anything that would happen to you but the normal behavior of law enforcement is to arrest you and let the courts decide. So I would try to be careful who you deal with and ask them what the law is to see if they actually know what the law is. It would be safer if they were a legal patient also, then they're somewhat covered by the MMJ law.