It shouldn't be surprising (or particularly upsetting) that trace levels of melamine have been found in US infant formula. Melamine is present in numerous everyday consumer products, and, like bisphenol A, it is likely that it will show up in processed and packaged foods. Modern technologies now allow us to detect very low levels of many chemicals (including the carcinogen, acrylamide, in cooked potatoes that has now gone down the memory hole), yet the amount of a particular toxin that you ingest is a key component in determining the overall dangers to your health. Processed foods come with one set of toxins and dangers, while unprocessed foods come with another set.
What is upsetting about this news is that it seems that, in usual fashion, the FDA has intentionally promoted a false sense of security for American consumers. Rather than make public the results of their tests, they released a vague, poorly-worded statement and kept the results of their tests secret from both the public and the formula manufacturers. Sounds an awful lot like Bernanke's position that telling us who got the $2 trillion would threaten the status of those businesses.
These bureaucrats are incredibly arrogant, deciding on their own what the dumb masses can and can not handle.