For freezing fish, being frozen does not actually kill any bacteria that may be present in the fish, but instead stops its growth, so freezing inferior grades of fish will not make it 'safe' to consume raw, the bacteria will still be there.
In regards to the farm raised fish, I wasn't talking about nice fish farms that actually take the time to give the fish natural food that it would typically eat in the wild, but rather the fish farms who are about mass-production. Most frozen shrimp you buy at a store, that come in a box are shipped over from Thailand which is the breeding ground for 80 to 90 percent of commercial seafood species..the improper production methods have devastated the natural areas surrounding Thailand and ways of production..which means who knows what we have been eating..