Word indeed often used in tv-series "The Sopranos". It derives from Italian 'questo cazzo', which
literally means 'this dick'. With a neapolitan dialect it is
pronounced ''stu cazz'', or stugats. Neapolitans use it when someone is
trying to tell or sell them something worthless (it can also be an indication for fake: a stugats watch). The American use has more facets, for example it can be used as a swearword towards a person.