The Chinese triads are also supposedly descended from the White Lotus Society. The purpose of the last incarnation of the White Lotus Society was to overthrow the Qing Dynasty, but when that collapsed on its own, a lot of society members were left with nothing to do. Being revolutionaries was basically their full-time job, and when that fell through many of them turned to crime. A lot of the skills in being a revolutionary are also useful in being a gangster, after all.