"The computer did it"

In The Register, the story of a man who got 7 days because when he signed up for facebook, it sent an invitation to “be his friend” to every facebook member whose email address was in his address book — including his ex-wife, whom he was under a court order not to attempt to contact.

He might of course have been lying, but if not he has been punished for what his computer, and facebook’s computers, did on his behalf.

The point is that the law has to decide how much responsibility a person has for what their computer decides to do.
Up till now, the assumption has been that whatever your computer does, is done at your request, and you are wholly responsible. This despite the fact that that has never been true, and is getting further from the truth every year.
There is no legal tradition to apply here. The nearest analogy to the relationship between a person and his computer is the relationship between a man and his dog.
People have kept dogs for thousands — most likely tens of thousands — of years, so everyone has a rough idea what the deal is. The general legal view is that you have a duty to keep your dog from causing harm under foreseeable circumstances, but there is a distinction between what your dog does and what you do. If your dog attacks a child, you are not guilty of Grievous Bodily Harm, but you might be guilty of keeping a dangerous dog. If your dog craps on the street, that is different than if you crap on the street, but you might still be fined.
If you are found guilty of not properly controlling a dog, you can be banned from keeping one. If your dog causes harm and is considered not to be controllable, the court can order it to be destroyed.
(If you deliberately cause your dog to kill someone, that is still murder of course, but your intention is crucial)
This is the only rational legal framework for crimes committed by a computer without the intention of its owner.