Apple co-founder and engineering genius Steve Wozniak has hit out at the FBI's attempts to force the tech giant to unlock an iPhone that belonged to a terrorist.

Mr Wozniak, known as The Woz, told Lateline that cyber crime was the greatest threat the world faced and he likened it to the cold war nuclear hysteria of his childhood.

"We used to fear the atomic bomb when I was young, and you used to come home from school and sirens would go off for a test on every corner," he said.

"Now we fear all the cyber attacks and hacking. What's the next one we're going to hear about?

"Is one going to come close to me? Is it going to hit me? Could they really take out our electrical system, take out our internet, how far can it go? And it's getting worse and worse year by year, not better and better."

FBI case is an attack on security, Wozniak says

Mr Wozniak said it was wrong for the US government to try to order Apple to unlock the phone used by one of the San Bernardino shooters

"What if the FBI was able to go to any company, any time they felt like it and said you have to build a product our way? I don't think that's right," he said. "What if the FBI can't get into a phone? They've still got all the records in this recent case, they've still got all the records from the phone company — of every communication that was made, of every SMS message that was sent."

Privacy: We have 'pretty much given it up'

Steve Wozniak and Steve Jobs in the early days of Apple, with Jobs in the foreground launching the first iPad. ( Reuters: Kimberly White )

The Woz, who built Apple's first two computers with Steve Jobs in the 1970s, said society had almost reached a point where privacy no longer existed.

"I mean cameras everywhere, our credit card and almost every action we take and where we go, we pretty much acknowledged to have given up a lot of that," he said. "[People] have a right to private things, I've a right to private thoughts too. I don't want somebody knowing how I feel about certain things, that's who I am and we've got to retain a bit of our humanness."

Wozniak doesn't believe in limiting screen time

Mr Wozniak, who was a star maths student, spent part of his career teaching young children about computers and he said the key was to let them have fun with it.

He said he would never limit a child's screen time, although he admitted he was probably in the minority on that point.

"I would never tell a kid to get off their phones, any kid doing anything technical, addicted to a computer, addicted to a game. No," he said. "Let them find themselves in the world. Don't force your values on them."

But Mr Wozniak said he would not be buying his new granddaughter her first computer, though he expected her parents would probably get her an iPad in a couple of years' time.

A giant of the tech world

The Woz left his role as vice-president of research and development at Apple in the 1980s and sold most of his shares, but he is still an employee of the company and receives an annual salary.

He remains a giant of the tech industry, having founded numerous other companies since his Apple days, and he is an Adjunct Professor at the University of Technology, Sydney's Engineering and IT faculty.

Mr Wozniak said once his work commitments reduced, he would like to move to Sydney, where his son and his family live.