I can go into LinkedIn and search for network engineers and come up with a list of great spear-phishing targets because they usually have administrator rights over the network. Then I go onto Twitter or Facebook and trick them into doing something, and I have privileged access.

The Americans are the most gullible, because they don't like to deny co-workers' requests.

My actions constituted pure hacking that resulted in relatively trivial expenses for the companies involved, despite the government's false claims.

Hackers are breaking the systems for profit. Before, it was about intellectual curiosity and pursuit of knowledge and thrill, and now hacking is big business.

But a lot of businesses out there don't see the return on investment, they look at it as a liability, and until they can understand that proactive security actually returns, gives them a return on investment, it's still a hard sell for people.

I got so passionate about technology. Hacking to me was like a video game. It was about getting trophies. I just kept going on and on, despite all the trouble I was getting into, because I was hooked.

I was addicted to hacking, more for the intellectual challenge, the curiosity, the seduction of adventure; not for stealing, or causing damage or writing computer viruses.