Every county is different. Some policemen believe there is no such thing as a medical marijuana law. Some are more tolorant.

I know a young lady that has MS and was on parole and tested positive. The judge upheald her use because of clear medical necessity.

The Feds can override any state action involving marijuana. ANY!! Which means even if you had one plant.

However, if you really are a medical patient, medical records and your doctor that wrote the authorization can usually defend you quite effectively. All I can say is it better be a legit illness.