Man... Did I do this...? :-)
Since we are on the subject... when I was younger I worked at a comic shop and another local shop had either Xmen. or TMNT, cant remember which, but in any case, they rented the machine from somewhere The manager somehow figured out to make it free play, which I didnt even know was possible... for the employees after hours... I guess someone got wind of it and the company took the machine back, stating they violated the rules, which they DID. But what is really stopping people from putting a mame cabinet in your local shop or whereever... hooking up the coin slot and NOT put a coin button on... Then using whatever front end you want... wouldnt you just pick the game you wanted, hit select and it would still need quarters right? I wouldnt put it past people, but I wonder if there are any cases of exactly this.
It reminds me of the people who stole PONG from that guy and then made arcades to put in donut shops and stuff, I guess the owner called a couple days later and said the machine was broke... it wasn't... I was FULL of quarters. :-)