I recently parked at charging station at SFO and returned to find the car unplugged and the SAE J1772 adapter was gone (now I have to purchase a new one for $95) and the charge port closed. There was not another car using the charger at time of return. I am guessing I may have broken protocol as I had the car there for three days (longer than it required charging) but I also understood that the adapter could only be removed by owner. Anyone else have this type of experience. What is protocol when you need to use airport charger but have multi-day trip?