A network of criminal organizations symbolically based in Hong Kong, though it was originally not primarily criminal and based primarily in Shanghai. It is similar to the Sicilian Mafia, and their Palermo is Hong Kong. They flourished in Hong Kong under the British and Japanese, but were largely eradicated on the mainland by Communist law. In time, the communists will remove them from Hong Kong, as well.
Triads are BAD. Drug pushing, prostitution and protection rackets, gun smuggling, and large-scale infiltration of the law. Chinese "mafia" that can fuck up the italians, the russians, the japs, and the blacks in many parts of the world. I'll smile when the last of them is brought into the teeth of Chinese justice.
Yo, you see that big ass dragon tattoo all over that chinese construction worker's back? He's a triad enforcer boy, don't fuck with him.