2 days ago
Facial recognition tech not a green light for surveillance
Analysis: The Privacy Commissioner's much-anticipated report into Foodstuffs North Island's trial of facial recognition technology (deemed an 'inherently invasive' tool) offers plenty to chew over.
Although the inquiry found the trial legal and generally compliant with the Privacy Act, important questions remain, and the report recommends that the technology stay under active review.
People who may have been paranoid about facial recognition technology being used to monitor their every move in supermarkets – what's purchased and so forth – can rest easy.
The commissioner found the technology was only used for the very narrow purpose of deterring serious incidents of violence and high-value retail theft by matching customers against a store's 'watchlist' (the image database of people of interest). It was not used for any other purpose, including minor retail crime prevention. The report cautioned against any future 'mission creep' in this regard.
Furthermore, although everyone entering a store with such technology had their face scanned, images that did not trigger a match against the store's watchlist were deleted almost instantaneously.
Meanwhile, watchlist data was deleted after two years in the case of perpetrators (and three months for their accomplices).
The number of people put on watchlists peaked at 1800 during the trial and was down to 1504 at the end. Crucially, watchlist data was specific to each store, meaning there was no master list shared within the Foodstuffs' network. This meant anyone who had been added to one store's watchlist could still shop elsewhere, including at a store without facial recognition technology.
Just as importantly, the criteria for being added to a watchlist were strict: either a conviction or a trespass notice was required. There was also de-linkage from other incident reporting systems, and watchlists were compiled manually.
A two-camera/two-staff fail-safe system was adopted for positive matches, and the commissioner's report found no bias in how watchlists were compiled as well as used. Children and young people were excluded from watchlists.
Meanwhile, Foodstuffs also maintained record keeping for judging the effectiveness of the facial recognition trial.
A 16 percent decrease in serious incidents and an estimated 21 percent decrease in shoplifting in the participating stores was recorded. In addition, 115 serious incidents were avoided (including 65 people deterred from entering and 50 others through staff intervention). However, some scepticism was expressed because of qualitative limitations in the overall data set (especially data from non-participating stores which operated as the control group).
The report documented at least two instances of misidentification, resulting in harm. Partly as a result, the accuracy rate required for positive matches was increased from 90 percent to 92.5 percent, although this still needed to be implemented. The Office of the Privacy Commissioner's Māori Reference Panel had opposed facial recognition technology in principle but gave advice enabling further safeguards to be adopted.
Finally, the report cautions that its findings are 'not a green light for more general use of facial recognition technology'. This is a salutary reminder that decisions to employ it should not be taken lightly.
Few small and medium-sized businesses will have the resources of Foodstuffs. The trial succeeded because of its investment in human time and effort. Technology, ultimately, is no substitute for this.
