Molybdenum is a naturally occurring element, along with the other 91 you learned about in gradeschool.  If someone thinks they can outlaw a naturally occurring element, then they're on quite an ego trip indeed!! 

But seriously, the state of Iowa, in its infinite wisdom, has made it illegal to sell any fertilizer materials that haven't been proven to be needed in their state (again, megalomania in gov't office!), and moly is one of those.  So far as I know, it's perfectly legal in all other 49 states to trade in moly fertilizers.

If you are short of moly on legume crops, you will get a nice yield boost from applying it.  Often it takes a number of tissue samples to identify a deficiency in a locale.  Oh, and you need to be super-careful handling those tissue samples -- vinyl gloves and all that.  Or just spray some strips of moly on your legumes and see if anything happens.