One mistake people make is underestimating the size of hacker communities, Calce noted. "I think people really underestimate how many scammers and fraudsters there are out there. There's a huge number and it's growing rapidly," he said.

Motivations are also changing. Ten years ago, hacking was about exploration, Calce pointed out.

"I think the biggest factor and biggest change we can see over the past decade is that money has become the No. 1 issue. It's the No. 1 motive for everyone these days it seems -- hackers, fraudsters, whoever you want to single out -- it's all about money now. They're not really doing it just to explore technology anymore," he said.

Calce's motivation was status. "I just wanted to be the best hacker and I was going to do whatever it took to be notified as one of the elite hackers in my community ... that was more my motive -- to experiment, see how far I could go and gain reputation and status amongst my peers," he said.

While 15-year-olds aren't the main concern for organizations today, Calce said they shouldn't be dismissed either.