Several years ago, a BJ player took AC casinos for more than a million dollars exploiting a flaw in the the decks.
He was able to cut the cards to the point where he could deal himself a ten. The more he won, the more they shuffled, and the more he won. They flew in experts that determined it was something in the cut but they couldn't figure out what.
After the fact, they realized it was a defect in the cards and had they not insisted on constant shuffles, the edge would have been much smaller. They went after the manufacturer, not the player. The simply banned him.