The adulteration of meat in this country is against the law. It is a health hazard. Different types of meat need to be cooked to different temperatures to kill bacteria, parasites and other organisms. Plus some people are deathly allergic to certain types of meat. It si also against many people's religious convictions to eat certain meats. Yet Dateline's survey shows adulterating meat to be a fairly common practice, even in some of America's most trusted grocery stores. Some of the problem comes from sloppy standards and lazy butchers - but mixing meats is also an easy way to raise profits.