Johnny knows little Jimmy from the neighborhood and tells him that he needs him to light a garage on fire to send a warning. Then when this is done, little Jimmy gets a couple hundred bucks for a job well done. Eventually in 10 years after a few more favors, Little Jimmy officially becomes an associate with the goal of becoming a made man. This puts little Jimmy officially on the FBI's radar. But little did they know that for the last 10 years, little Jimmy has been doing favors for the mob.
Unless they are really good at counter-surveillance, little Jimmy is going to be on the FBI's radar sooner than that because FBI is going to start asking "why is Johnny meeting this unknown kid in restaurant parking lot" or "why is Johnny's known associate Tony frequently calling this unknown kid with crypic messages after he talks to Johnny". If Jimmy comes into contact with someone under surveillance or wearing a wire in his ten years of doing "little favors", he's going to be checked out long before he becomes a close associate or made.
