Aside from any moral qualms about the legitimacy of such a book (of which I remain neutral) this is clearly not written by an 'authority' on this subject, so any serious hacker would find it no more dangerous than halitosis in a gas station.
Lots of waffle and posturing. Not convinced he actually understands the more advanced 'code' snippets he introduces (e.g. he manages to confuse a c 'header' with a 'library', also why would any serious security hacker write a keylogger in pascal!!!? Many parts are REALLY badly explained and have basic errors for a 2nd edition (see p356 - the first Xor table has a basic error in third row). Several bits of the text look suspiciously familiar (i.e. possibly cut and pasted from unacknowledge sources, which might explain the inconsistencies).
I gave two (generous) consolation stars because (a) the breadth is to be commended (at least he tried), and (b) the fact that you can still pick things up interesting snippets from this book; so long as you suspend the urge to yell WRONG! at it, and (c) Contrary to the previous reviewer who gave it 5 stars (a 'friend' no doubt) this book states on the last page that it is aimed at 'beginners'.
Unimpressed...