Here is an interesting article which reports that 26 slot machines were apparently misprogrammed at a casino in Indiana, so that ...
"If you put in $5, you got $10. If you put in $20, you won $40 -- without pressing a button."
See http://tinyurl.com/3ckdx
What is fascinating is how this was detected. "According to a report from the State Police gaming division, casino security officers saw a man cash out his bet without playing a single spin Dec. 7." I would never have guessed that anyone would ever pay any attention to someone cashing out after putting in their money and not playing; people change their minds all the time and sometimes they do it just to get change for a large bill so they can tip a waitress. And think about it; unless security was looking right over this guys shoulder at the time, why would they be paying any attention to whether he was getting back more than he put in (I'm surprised that they knew which size bill he inserted, and then paid enough attention to the coins coming out to realize he was being paid double. (If it was a TITO machine, that's even more bizarre).
Bill Velek