The penny has finally dropped about privacy, as the public wakes up to mass online surveillance, the privacy commissioner says.

Reflecting on a year that uncovered global bulk internet surveillance and potentially illegal spying by our own spy agencies, Marie Shroff said Kiwis were increasingly concerned about losing control of their information.

"There is a loud sound of penny-dropping all over the place as people are realising the full implication of collecting all this data, the huge risk that it poses, the opportunity for misuse."

She said it was unclear how mass online surveillance by the United States and others were affecting Kiwis because there was so little information.

However, she rejected the suggestion that the horse had already bolted on privacy. "That is a myth perpetuated by the people that have the most to gain from collecting and using information. We shouldn't allow ourselves to be conned by that sort of attitude."

Leaks by former National Security Agency (NSA) intelligence analyst Edward Snowden have revealed the mass harvesting of citizens' internet and phone data, both in the US and overseas.

Closer to home, it was revealed the Government Communication Security Bureau (GCSB) may have unlawfully spied on 85 New Zealand residents, including internet entrepreneur Kim Dotcom.

Unsurprisingly, both the GCSB and the Security Intelligence Service (SIS) were the subjects of privacy complaints to the commissioner in the past year.

The GCSB was the subject of 19 complaints, only one of which was found to have substance, while the SIS was the focus of 13, three of which were substantiated.

Both were dwarfed by complaints against other government agencies, with ACC receiving 79 during the year.

Overall, 842 privacy complaints were received, down from a record 1142 in the previous year.