Several grocery store chains in the U.K., including Waitrose, have announced that they will stop selling energy drinks that have more than 150 mg of caffeine per liter to customers under the age of 16.  

This is a voluntary measure that the chains have taken because of concerns raised in Europe over whether energy drinks are appropriate for children.  Both the EU and the UK currently require high caffeine drinks to have a warning label about the use of the product by children and women who are pregnant or are breast feeding.  

With the pressure mounting across the pond, we'll have to keep an eye on this issue in the United States.