Vending Kegerator/Kegbot hack?

Theoretically could you hack the kegbot by adding a flow meter and solenoid valve so that certain accounts could only pull so much beer out of the tap and when that amount was reached the solenoid would close and nothing would come out of the tap until a another credit was inserted? What I'm asking, putting aside all legality issues at the moment, could you make a robotic bartending kegerator where you would either insert money or swipe a card, pull the tap handle and it would dispense a pint?

I would think so. I work for a very large company and traveled to one of our locations in Denmark. In the company cafeteria they had a coin operated beer keg. You bought a token from the sandwich machine and fed it to the beer machine. It poured you a beer. Loved the idea

I've used coffee vending machines. You pay and it dispenses a cup then fills with hot coffee.
Swap the coffee for beer and done!