mis labeled seafood
As a kid I remember going to a place to buy fish with my dad. He never bought scallops there, because "everyone knew" that they punched ""scallops" out of shark fins. I don't know if it was even true. Years later, a friend in the scallop biz (real scallops) told me that shark fins are worth more than scallops.
Flash forward to today........they were talking on a local radio station about a restaurant that got caught using rings cut from the back end of a pig in place of calamari. I wish that I remembered the name of the place.
Not seafood, but a local strip club has been punished for serving cheap booze out of expensive bottles.
You need to trust the places that you go.