One of Australia's most senior spy chiefs says the threat that local intelligence might have a rogue insider like Edward Snowden is real and one that security agencies are increasingly concerned about.

Steve Meekin, the deputy secretary of intelligence and security, is directly responsible for the operations of the Australian Signals Directorate - our equivalent of the National Security Agency (NSA) in the United States.

Snowden is holed up in a Russian airport after being charged with espionage for revealing the NSA has access to vast amounts of internet data such as emails, chat rooms and video under a government program known as PRISM.

In rare public comments, Mr Meekin said the revelations cut to the core of privacy and probity, but there was a fair bit of mythology in the reporting about what has occurred.

Mr Meekin would not comment on Australian capability but said any involvement Australia had in the PRISM program was consistent with Australian law and that "Australians should have confidence that what we do is in accordance with the law".

In his address to a seminar at the University of Canberra, Mr Meekin said the insider threat is something that Australia's intelligence agencies have to live with.

He said while the sort of "overzealousness" characterised by the Snowden case in the US is a significant risk, security clearances in Australia are constantly reviewed.

Australia's security agencies have recognised that technology has meant that individuals within the system now have more access to information.

Mr Meekin said the situation has to be well managed and requires "good, strong leadership".

He said managers have to be on the lookout not just for potential "traitors" but also for employees who might find themselves confronting mental illness or messy and difficult personal circumstances.

Mr Meekin also warned the threat of cyber crime is increasing rapidly and increased significantly in the six months between October 2012 and May this year.

The number of cyber security incidents identified by or reported to the Cyber Security Operations Centre was 1,259 in 2011 and 1,790 in 2012.

There were 789 incidents recorded between January and May this year.

Mr Meekin said the threat of cyber attacks come from a range of sources including "individuals, activists and organised criminal groups".

He said more than 80 per cent come "directly from foreign states" and 65 per cent of cyber intrusions have an economic focus.

But he said the Australian intelligence community is "confident that 85 per cent of those attacks can be mitigated."

Mr Meekin said keeping across technological change is one of the biggest challenges for the intelligence agencies.

He said data storage is becoming a concern for Australian intelligence and the need for data storage is expected to grow, but "no agency would have the capability of hoovering up everything that was on the net".