An undercover federal agent locates a group of men who seem to be frustrated with the government in a rural area of Indiana. The agent begins talking to the men about planting a bomb at a rally for a local politician. The men laugh and joke, but then the conversation gets serious. The agent gives advice and tells the men where they can obtain the materials. After a couple of weeks of conversation, the men meet the undercover agent to assemble the bomb and plan the crime. Before the crime can occur, FBI agents swoop in and arrest the men with the evidence collected by the undercover agent.

What criminal defense can be used? Explain.