|XP is just a number|
If such material wasn't published at all, by well meaning organizations or elsewhere, what would happen? Only those with enough brains to learn programming, without being given any security related tips or code, would be able to write new computer cracking software (and protection). Is that good or bad? For crackers, it would create a roadblock. For real programmers, they would have had to learn to program anyway, so it's not as bad.
In the dark ages, the few fortunate enough to be literate were the recipients of enormous benefit. And everyone else, well, they got screwed. This was a good arrangement (seemingly) for the literate few; they got to have cheap labor and could tell their 'loyal' subjects anything they wanted, claiming it was God's will, quote a few scriptures (which nobody else could read), and their subjects would be compelled through force or fear to follow along.
But it was a false superiority, for during that time real innovation ground to a halt. It seems that it takes many minds, not just a select few, to turn the wheels of progress for a society. It wasn't until the renaissance that things began to improve, hand in hand with the improvement of the literacy rate. But remember, this came after the moors almost wiped the "keepers of truth" (the Christian literate) from the face of the globe.
Obscuring knowledge is rarely the key to safety, security, and progress. It is generally a key to power abuse, an impedement to societal progress, and in the end doesn't even really benefit the few in posession of 'literacy'.
Everything in that book is going to be pretty much common knowledge, readily available either from legitimate sources online, or through illegitimate sources. Either way, the book, as I understand it, is geared toward helping systems administrators and programmers to understand the beast they face, so they may refine their approach to slaying it. Keep books like that off the shelves, and the knowledge won't go away, but the knowledge to protect ourselves from that knowledge might suffer.
Your points earlier were unsubstantiated, blamed the wrong people, shouldn't have blamed anybody at all, and were too diverse to be effective. O'Reilly isn't the enemy. Knowledge is not our foe.