Andre Nestor from Pennsylvania is facing 650 felony counts of theft, criminal conspiracy, computer trespassing and other charges. Federal agents say Nestor and an accomplice knew about a software glitch in a high paying slot machine. They say the two convinced casino employees to change things like the volume and brightness of the screen and engage a “double-up” feature on one machine with a glitch.

From the Post Gazette:

Normally, such a feature would allow a player to risk doubling his winnings or potentially losing them all. The double-up feature isn’t usually enabled on the machines in part because it’s unpopular with most gamblers, who are unwilling to risk large amounts of money.
When the correct sequence of buttons was pushed, the machine displayed false double jackpots. No casino officials noticed because the bogus jackpots weren’t being recorded in the machine’s internal system.

This went on for quite some time, and federal authorities say Nestor may have made off with as much as $1.4 million from various casinos.