Raw milk, the unpasteurized white stuff that has the audacity to come out of a cow bearing microbes, is illegal in the U.S. and in most countries. Heating the stuff got rid of over 90% of the cases of things like e-coli. Not bad. On the other hand, there are (possibly credible) assertions that pasteurization also kills a lot of good bacteria - both those that help and those that hurt us just enough to spark an immune response.
Now, I am not for overturning the raw milk ban. I think that the cost of offering a product known to carry dangerous pathogens to a public that is rarely educated enough to understand what that means will surely result in higher public-health costs.
That said, I wonder whether a limited mechanism for acquiring the stuff might be reasonable. Raw milk is a small enterprise, so prices will be high. They can be higher still if you regulate the practice and require people to test cows for the bacteria we worry about most. That will drive the cost to at the very least double that of regular milk, so only the truly committed will buy it. Add to that a continuing prohibition on serving it to anyone under, say 18, and I think you have a reasonable solution.
I understand that the claimed immunological benefit of raw milk is best felt early in life, but I'd need to see hard evidence on a large scale showing that it is so before I would permit parents to serve it to kids willy nilly. And this isn't the first product we won't serve to kids...there is no reason to fear feeding honey to infants now that it is pasteurized, and absolutely no ill-health effect of alcohol on the body of, say, an 8 y.o., but we regulate both of those due to...you guessed it...the public health cost.