Surveillance cameras are now so powerful that they were able to zoom in on individual spectators at the Rugby World Cup and read their text messages.

Details of police monitoring used for the first time during the tournament were discussed at a privacy forum in Wellington yesterday, at which it was revealed that the average person is digitally recorded about a dozen times a day – and even more if they use email and social media frequently.

Superintendent Grant O'Fee told the forum how one incident at the Rugby World Cup "tweaked in my head" a concern about possible privacy breaches.

Camera operators who were scanning the crowd for unruly behaviour or suspicious packages chose to zoom in on a person who was texting.

"He was actually texting about the poor quality of the game of rugby. But it did occur to me that there was an issue there - had he been texting something that was of some consequence to us, there may have been privacy issues."

He confirmed later that the level of monitoring used during the World Cup would continue for all big test matches.

CCTV now operates inside many buildings, including hospitals, supermarkets, malls, and around public toilets.

There are 11 cameras in Wellington city centre, recording 24 hours a day.

In Britain, drone cameras, mobile cameras on cars and cameras on police helmets are in frequent use.

Soon, technology will exist that can pick up on raised voices, and sniffing devices will be able to detect drug residue, Stirling University lecturer William Webster told the forum.

Privacy Commissioner Marie Shroff said some overseas developments were amazing and she imagined there would be concern if and when that technology was implemented in New Zealand.

Civil liberties lawyer Michael Bott warned against becoming desensitised to digital surveillance.

"It's quite worrying when we, by default, move to some sort of Orwellian 1984 where the state or Big Brother watches your every move. The road to hell is paved with good intentions and we don't realise what we are giving up when we give the state the power to monitor our private lives."

Ms Shroff said that, although reading someone's text messages in public could cause concern, the legitimacy of the action depended on what it was used for.

"We need to be aware of that – that potentially texting in a public place can be caught on a CCTV camera. If the text showed the person was plotting a riot or something, then it might well be legitimate for the police to use that under the coverage of exemption for law-enforcement activities.

"But if they were to use it simply out of nosiness, that might not be exempt," she said.

Former detective Trevor Morley said the average person had nothing to fear if they were not doing anything illegal.

"The only people who need to be concerned about these advances in technology that the police are using are the people who are abusing it, or the people who are acting in an anti-social manner."

Ms Shroff added that education and awareness of surveillance tactics were crucial.

"The law can do only so much. There are many, many great uses for the technology and we just have to make sure we balance those so it doesn't become ridiculously intrusive into our lives."

YOUR DIGITAL FOOTPRINT

Your Digital FootprintAn average person is digitally recorded about a dozen times a day, and more if they use email and social media frequently

There are 11 CCTV cameras throughout Wellington city centre, recording 24 hours a day

Movement can be tracked through mobile phones and computers

Work access cards can be used to track your location

CCTV operates inside many buildings, including hospitals, supermarkets, malls, and around public toilets

Any online search, online purchase, eftpos or credit card transaction, or smartcard used for car parking is recorded

Social media usage is tracked and used for marketing and advertising.

Any information put online is there forever

Some smart electricity systems track usage

- © Fairfax NZ News