I heard of a story of someone's BTC being hacked despite all measures being taken, such as Paper Wallet, Truecrypt, and offline access, but they still got hacked.
It does make me paranoid, but I guess that's just some of the risks of using Bitcoin.
"Humans are the weakest link in IT Security Chain"
Humans are the weakest link in general. I vote we move to a system with robot overlords. And robot workers. In fact, lets get rid of humans and just have robots.
But yeah, a good penetration tester will be a good social engineer too. Charm and a few good words can get you in a private network relatively easily.