This is what happens to the fats during pasteurization. Cream & milk that doesn't have them is homogenized (forcing fats through tiny holes) or otherwise filtered to remove them. They probably aren't any worse than the rest of the pasteurized milk - you'll find that "clumping" no matter what pasteurized non-homogenized "cream top" milk you buy. I won't drink that stuff anymore, though - only raw milk from the right dairy.