[boardstrapd]

Medicann is NOT accepted everywhere. In Oakland, I went to Purple Heart with my brand new Medicann card & rec, only to be told they don't accept Medicann. Medicann gives a website, pcfrm.org, which lists the dispensaries that accept Medicann. I have no idea how often they update it, though.
I've yet to hear if law enforcement recognize Medicann or not. Oakland police are supposed to recognize the OCBC card, so they won't do anything to you if your caught medicating. Basically everything is really up in the air at this point, since medical cannibas is still in the infancy stage and regulations haven't been ironed out yet.

What I tell other prospective patients is if you want to save money, are already familiar with your conditions & treatments, and don't mind not having access to as many dispensaries as possible, go with Medicann. The Medicann card is NOT the same as the 'state-issued' card, it's simply the same as the recommendation letter.
If you really want a quality healthcare experience, avoid Medicann and go to another physician who specializes in cannabis recommendations. You're more likely to get helpful info regarding the use of cannabis for your specific conditions.
Getting a card, like OCBC, is not required. Any card, whether 'state-issued' or not, doesn't guarantee protection during a police encounter for using your meds. It depends on the local laws/acceptance, and how self-righteous the officer is.