A similar action was recently taken against the makers of Airborne with the same idea - there was no proof of their claim that the product reduces the duration of a cold. Having used Airborne many times, I can tell you from personal experience that it does, in fact, reduce the duration of MY colds.
My personal preference whenever available is to eat foods rich in whatever it is that I need, rather than swallowing yet another pill to achieve that effect. I don't think it really matters which yogurt you eat, as long as you eat one.
As for McDonald's - sounds like lazy parents who won't taken any of the blame to me.