The policy that really struck me was that in the medium security prison, chewing gum was contraband for prisoners and visitors (IIRC it was actually a maximum of ~$1000 for bringing in a pack of gum). The reason for this is that the prisoners can use it to clone a key or jam a lock open, which meant potential escape of violent prisoners from secure areas. The staff actually have to check every lock before they insert a key (it jams the pins in the right position, allowing them to insert something as simple as a plastic knife and they're able to open the lock).

Minimum security never had that restriction, it's generally run on an honour system. The prisoners in there have all committed non-violent crimes, and generally they were more polite and respectful than people in the general public. At least that was my experience, there was a lot of polite people in the medium security, but the guards required a 10ft distance between prisoners and visitors at all times, just in case.