Would lean towards making it have an open, wireless mesh network, so that devices could connect online through it. Electrical socket for charging, though anything "too advanced" like a USB system would become outdated, or easily vandalised. With probably a direct headset/button for emergency services, and would probably mirror what sort of systems metros in large cities follow, including fines. So pretty much a black box in a wall, that has an interface for emergency situations, and an electrical socket beneath. Anything else is going to get pissed on literally, and figuratively.
Would lean towards making it have an open, wireless mesh network, so that devices could connect online through it. Electrical socket for charging, though anything "too advanced" like a USB system would become outdated, or easily vandalised. With probably a direct headset/button for emergency services, and would probably mirror what sort of systems metros in large cities follow, including fines. So pretty much a black box in a wall, that has an interface for emergency situations, and an electrical socket beneath. Anything else is going to get pissed on literally, and figuratively.