Seriously, people?
Looking at a can of Monster Rehab (lemonade/tea one), there is a warning label that pretty simply says 'don't overdo it'... for those who want details 'Consume Responsibly - Max 1 can every 4 hours, not to exceed 3 a day'.. blah blah blah...
So technically, there is a warning label.. Just because people these days are idiots, have little idea of self control (Look at facebook if you REALLY need proof of this), and the general idea of people don't need to police themselves because 'big brother' or whomever will do it for you.
These warning labels are you're basic common sense, and there should be no need for them. The main reason that they are there are because some grade-A moron didn't think.... period... and used a product in an amazingly boneheaded way. Do we REALLY need a tag on an electrical device that says 'do not use in the bathtub... REALLY?
Focus on what needs regulations. the government, corporations (not their products, the C*O's, etc), and things that are more rapidly killing our country than energy drinks.