+1.Ultimately the only way to fairly allocate limited resources is to charge for them.
Here's just a few random examples of how I've heard of people have abusing free charging:
1. Nissan dealers - just about all dealers have had issues with people plugging in and hopping into another car while leaving the car there on the charger ALL DAY and the dealer stuck with a car blocking the station.
2. Mitsubishi HQ - Volt driver would pull up in the evening with bike on the back, plug in the car and ride off picking up the car in the morning.
3. Blink DCQC stations - people complaining about the $5 charging fee recently implemented because they were counting on them to be free while they drive 120+ miles/day. Or people using DCQC as their only method of charging simply because it was free.
Tragedy of the commons comes to mind...