According to my deep knowledge of US laws, Mc Donalds could decide to increase their prices by a factor 100, make the cheese burger 20 times cheaper, it would still be legal as long as they sell what they advertise.
But yes... on the point... this is ridiculous... and will end up killing all commercial creativity in the US because legal teams - hired to protect companies from other legal teams - will stop every initiative that may have the sligthest chance of opening the door to a court suit.
At the end of the day, this is a coup d'etat from the legal community who is pulling a huge amount of money towards them at the cost of much more valuable applications, such as curing people from cancer.
Reduce the number of lawyers by a factor of 5 and the number of litigation will drop accordingly.
Cheers,
Bernard