Hacking into any government computer system should be punished. I actually think hackers are the only necessary evil I have ever come across. Without them we would not really know just insecure and how crappy some of these networks, programs, and OS's are. Do I agree with everything they do, talking real hackers here? No, of course not, but they do serve a purpose and I do believe the majority of real hackers are satisfying their curiosity and the challenge, even if it is wrong. This is not giving them an excuse mind you, please do not take it that way. Most of the time when a dollar amount is applied to show damages, it is not a physical damage but the time taken out to fix how a hacker got in in the first place and the dollar amount is usually overblown.
Should he be punished? Yes. The likelihood, and I hope it happens for McKinnon, is he will serve jail time and be fined quite a bit, however after a while in prison the U.S. or even the UK will come to him and offer him job.
As for whoever said hacking should = death. What? Please! That is going way to far imo. As already stated when murders and child molesters and several other types of crime and criminals get only jail time and then, in some cases, released their is no reason to sentence a hacker to death. Evidently whoever said that does not believe in second chances, or at least cannot determine with good sense when and who should get a second chance. Too bad, just remember everyone makes mistakes, just hope whoever said this does not screw up cause if he has to answer to someone with that mentality, you are so up a creek and if that happens, I hope you don't go "I just made a mistake." It would be hypocritical.