Computer Crime, Then and Now: Here’s a good post from Jeff Atwood that lays bare a simple truth:
Social engineering is the most reliable and evergreen hacking technique ever devised. It will outlive us all. […] If you want to engage in computer crime, don’t waste your time developing ninja level hacking skills, because computers are not the weak point.
Some great book recommendations there too. The Cuckoo’s Egg was awesome.