The Cuckoo's Egg (Score 2, Informative)

If you want good books that show what hackers were doing to military installations and whatnot in the mid-80's, try reading 'The Cuckoo's Egg' or 'Masters of Deception'. These books will give you a good look at how Tymnet was more full of holes that Swiss cheese at that point is history. 'The Cuckoo's Egg' is better, but they are both enjoyable, from a hacker's perspective.