For dispensaries, it must be within an "enclosed, locked facility." If growing outdoors, that means 10' walls, etc. If growing indoors, it means "A building with four walls and a roof or an indoor room or closet."
And then the specifications after that (two references in the latest draft rules), it is for "an enclosed, locked facility."
Meaning that the enclosure must be locked. There is no specification given as to the locking device, so presumably a $20 Kwikset deadbolt on each door of the facility would suffice. The law seems fairly ambiguous as to whether the individual room/closet is to be locked if growing at home, but figure if there are kids in the home and the grow room isn't locked, the state'll probably want to take your kids away.
Not that you need to put your Oxycontin under lock and key, but, you know, marijuana is so much more lethal and stuff.
Look at it this way: there needs to be a lock on doors such that there is no way the person on the street can get to the plants under cultivation through a door without a lock.