Yes, they are breaking federal law if they are getting it from marijuana, but may or may not be breaking state law depending on the state. The ones using CBD from hemp are not breaking any federal or state law in any state as not every state has legal mmj laws. And yes, those in legal MJ states have the option to go buy from a local dispensary where those that live in a state that doesn't have legal mmj don't have that option.
MJNA's hemp CBD products, legal in all 50 and Federally and legally sold internatinally also.
A medical marijuana patient is already breaking federal law so I don't think the argument that the hemp CBD is legal when Cbd's extracted from marijuana are not so they will buy them holds any water since they probably go buy marijuana products regularly of not daily at their local dispensary or delivery service