I was going even simpler. When the person is finished with the pod, and the door closes and locks, the pod takes a photo. When the next person pays and the just

I was going even simpler. When the person is finished with the pod, and the door closes and locks, the pod takes a photo. When the next person pays and the just before the door unlocks, it takes another photo. No computer analysis, no nothing. If there is a complaint or a need to check the photos, someone can. Automation can come later. Add a reputation system to catch repeat offenders (with proof) and you're done. Cheap and simple.