I am not a lawyer, just interested in the laws that effect me. Even a lawyer probably couldn't tell you with certainty what the outcome would be, due to the complexity of law. So, take this post with a grain of salt. Also, the comments I make in the following post are in reference to the USA. I do not know enough about other countries laws to make any comments.
Chances are that most of those intrusions that Norton is detecting are nothing but scans. There are many people who will scan other computers for open ports. Some do it for fun, some for malicious purposes. Scanning is technically illegal, but little would come of it if you reported it. A customer means money to an isp. If they haven't done anything damaging it's unlikely that they would drop him/her.
As for entrapment and honeypots, there really is no such thing as civil entrapment. Entrapment is a term used for criminal cases, and it only applies to agents of the government. A citizen working on his or her own can "entrap" you and the government can still use any evidence from this against you in a criminal case. Now, reports may have been using the term entrapment, but I think that it is an incorrect and misleading use of the term. Even given that, just having a honeypot is not "entrapment" per se. You would have to entice, force, or otherwise get them to do something they did not have the intent to do. The only way I could see this happening is if you sent an email that said, "Come to my honeypot and see if you can hack it." In this case, you made an invitation. Thus, when somebody comes and does just what you invited them to do, no law (criminal or civil) has been broken. If no law is broken then there can be no entrapment. Now, if you sent that email about somebody else's server, then you would be responsible. However, even with you being responsible, that wouldn't necessarily negate the hackers responsibility. That being said, judges in civil cases have great lattitude. They might decide to infer (or if there is evidence) that your intent in setting up this server was to attract these types of people and that you did not take the proper security measures, they may throw it out.
As for the idea of suing the music industry for hacking into your computer, don't count on it. First, you would have to show sufficient damages. If they just scanned, then there is nothing to sue about. You could try to get the police to go after them on criminal charges, yeah right. Another thing to consider is that when there is not specific case law to support either way, often judges will look to what is happening on Capitol Hill. Currently there is a bill in Congress that will specifically allow the entertainment industry to do just this. Not only that, but if this bill is passed, it will remove any liability they might have for deleting the wrong files, damages they may cause to the system, etc.... Essentially, this bill will allow them to use hacking, virii, trojans, and whatever else they can think of to get into your computer. It is fairly broad in its scope (it is not specific at all about what technologies it will allow content copyright holders to use), and if it does pass it may be reigned in on appeal because of this. However, the fact that this bill is in Congress would likely mean that an attempt by you to sue would go down in flames (especially if you were serving up copyrighted materials).
