Here is a story from Greenhouse Grower about an unnamed illegal propagator of knock out roses being caught and fined. The nursery was in Central Florida but will remain unnamed due to the clauses of the settlement.
Any plants that are patented are the property of the patent holder and the propagation of those plants will need to be allowed or permission given from the patent holder. This is an easy financial risk to eliminate from your business operation. I have seen people inspecting large nurseries for the potential of illegal propagation. Here is the link to the rest of the story.