The depression of the 1930s led people to desperate measures to survive. The marathon dance craze, which flourished at that time, seemed a simple way for people to earn extra money dancing the hours away for cash, for weeks at a time. But the underside of that craze was filled with a competition and violence unknown to most ballrooms.
In the back of my head I knew that they had dance marathons back in the Depression. Back in the old days equals tame, right? Nope.