Meh, tainted food is 
good for you!  Builds up the immune system! 
Personally, I don't buy frozen fish, I don't shop at WalMart, and I live in a place that has so much fresh fish from nearby water that I don't really worry about it in restaurants... I have a rule about eating fish in any place that lacks a coastline.  I suppose I ought to check the side of the box of Gorton's fish sticks, the only kind of fish I eat that isn't immediately recognizeable.  
But then, I don't really care.  I eat medium-rare beef all the time, I'm not picky about how well-prepared my chicken is, and I kept on eating spinach when that was supposedly tainted, too.  I really don't think it's worth worrying myself about.
But I think the main point is that you have to be willing to pay more for quality products.  The only reason the Chinese imports are proliferating all over the place is because people want their stuff cheap.  I figure that there's a 
reason "generic whitefish" (there is no such creature) is cheaper than a pound of visibly fresh salmon with the name of a local fishery on it.  And if a restaurant serves all of its fish breaded and deep-fried, you have to wonder why you're not 
allowed to look at the fish in the nude.
When people stop eating this kind of fish in droves, there will be changes.  Economic boycott is immensely useful if you get enough people involved, and a media-induced panic will usually do it... just ask Wendy's about 
their loss of sales when that woman claimed to find a finger in her chili.