Cheerios, the 'Terribly Adult Cereal' w/Stan Freberg

I can relate to this commercial, as I like Cheerios, I like Stan Freberg and I don't like headaches!! But my, have times changed!! I frequently see parents with lil' plastic Baggies of this 'terribly adult cereal', feeding them to minors, sometimes as young as teething age?? Is this legal??!!