A recent article in the Nation by Eric Schlosser author of "Fast Food Nation," may be of interest. I knew about it before this, but hadn't realized the proportions of the problem. (Personally, I never eat ground beef unless I grind it myself. I use a meat grinder attachment on my Kitchen Aid. Originally my motivation was taste, now it's safety.)
Schlosser writes, "The defective product wasn't fiber optic cable, energy futures or some esoteric financial instrument. It was bad meat--almost 19 million pounds of beef potentially contaminated with E. coli O157:H7, enough to supply a tainted burger to at least one-fourth of the US population."