Sorry brother, did not mean to terrify you. That sheriff in the article is especially into that kind of crime, he's kinda creepy actually when you here him talk. If you just downloaded half of something and then deleted it I really don't think you have anything to worry about with most professional law enforcement. Despite what they could possibly get you for if your hard drive was not clean, they would see the incident as a very non-intentional one based on that. And the fact is that if you have not had anyone knock on your door yet, very slim chance that you are ever going to. Real federal law enforcement is going to be looking for regular activity and then move in directly after a download or an exchange of some kind so they know they have current, real evidence; not to waste their time with an old half-event like yours. They want to catch people who are actually doing something wrong. Follow the good advice presented to you here, please stay clear of dangerous activity but please have peace of mind also my friend. You are going to be fine.