I think that there is a fundamental difference between computer crime and other kinds of crime, where "insanity", or "drunkeness", or "duress" could be used successfully.

Barring the wonder-tool skiddie script of the moment, most attacks that cause damage which makes it worth the expense to investigate/prosecute, take time.

Time means deliberation, planning, things that make the difference between shooting someone in an emotional moment and making an elaborate plan to snuff them and try to get away with it.

Any large corporation with good security policies should be difficult enough to break into that calling temporary insanity would be incredulous.

The defense would have to show that the attack happened quickly, did its damage and then left the defendant wondering what the hell the did. (and it would be even better if they could feel remorseful).

Of course, in the revenge department dealing with privileged information, it could be reasonable to think that they new a hole, weakness, or access code that would allow them to gain access without much difficulty, such that half a 1.75l of Gordons vodka in they decide that its a good idea to stick it to the man taht done them wrong. But, a situation like that SHOULD be avoidable with really strong, effective, and followed security policies.

So, I have mixed feelings. The biggest problem I have is that in a jury based trial it would be unlikely to have jurors that understand the technical mumbo-jumbo that would be used. It would be for a lay person to understand certain nuances that an info-sec professional might.

Just my ramblings,
Dhej