I've said before that transparency in our food is important for us to be responsible omnivores. Since that isn't possible, I don't think we should be omnivores. But for those who believe that there is enough transparency in our food, you might want to look at this link. Two high school students, sequenced the DNA from a variety of food sources and found that they were not as advertised. High quality caviar was in fact from a very common "low grade" source of caviar, the Mississippi Paddlefish. Goat's milk cheese turned out to be made from a cow.
It makes me worry as a vegetarian since if even the listed ingredients aren't accurate, then how can we as vegetarians be sure that our tofurkey is really just tofu?