In the 1920s the Binh Xuyen started as a loosely organized criminal coalition consisting of hundreds of armed gangs led by various leaders, extortionist and contract killers. Their history consisted of tapestry of piracy, protection services, kidnappings and extortion of rich families, operating brothels, drug smuggling, and assasination. The Binh Xuyen have sometimes been miscalled a sect, but they were not religiously oriented and don't seem to have had much of an actual political ideology outside of a vague Vietnamese nationalism.
One of their most notorious leaders, Ba Duong, become the kingpin of most of South Vietnam by 1945. Under his leadership the Binh Xuyen would eventually make a transition from outlaws to revolutionaries as they became involved in politics between 1945 and 1955.
Under the command of Major General Le Van Lien (also known as Bay Vien), the Binh Xuyen Forces were later recognized as an independent non-communist military force within the Vietnamese National Army. During this time the Bình Xuyen managed to continue to fund itself with its organized criminal activities while also effectively battling Communist forces. In 1955, a month-long battle (often referred to as the Battle of Saigon), between the Vietnamese National Army (later to become the Army of the Republic of Vietnam) and the Binh Xuyen's militia forces resulted in the defeat and disbandment of the Bình Xuyen and their criminal operations. Text Source: Historical Flags of Our Ancestors (http://www.loeser.us/flags/cold.html#bxf) Pete Loeser, 15 February 2015
"Binh Xuyen Force (Vietnamese: Bộ đội Bình Xuyên or Lực lượng Bình Xuyên; Chinese: 平川派軍 or 平川力量), often linked to its infamous leader, General Lê Văn Viễn (aka "Bảy Viễn") was an independent military force within the Vietnamese National Army whose leaders once had lived outside the law and had sided with the Việt Minh. During its heyday, Bình Xuyên funded itself with organized crime activities in Saigon while effectively battling Communist forces. It was called: Binh Xuyen Group, Binh Xuyen Force and even Binh Xuyen Volunteer Police." Esteban Rivera, 23 April 2016 Source: Wikipedia article