UK privacy activists raise fears over social distancing tracking

[ Original @ the Guardian ]

Privacy campaigners have warned that a UK government plan to use mobile phone data to track the success of the social distancing policy needs to be carried out with “radical transparency” because of the authoritarian possibilities.

The Guardian reported on Thursday that BT and O2 have talked to the government about providing the data, which would be delayed by 12 to 24 hours and stripped of individual identifiers, to help the government assess whether people are following advice to avoid pubs, bars and restaurants.

Big Brother Watch said it was concerning that the deals had been struck in secret. “We need further explanation and much more transparency,” said Silkie Carlo, the privacy group’s director.

“The public needs to trust phone networks at this time, especially to seek health advice and social support. It can be very hard to anonymise location data and so the government should be radically transparent about any tracking if it is to maintain public trust.”

James Cheshire, a professor in geographic information and cartography at University College London, said individual data was less useful than many assumed. “There’s always a tendency to think about the tracking of individuals but actually, in practice, that’s not what people are interested in doing,” he said. “They want to look at the general activity levels.

“The data the operators are able to give is these general activity levels,” Cheshire added. “If a certain grid square in central London, for instance, two weeks ago had 5,000 people in it, and today has 100, you’d be able to identify areas of the city that are still much more active.

“If it got to a point where you were trying to prioritise interventions, and it was clear that, hypothetically, the West End has shown much more diminished activity but the outskirts of London are lighting up because people are still going out in their local area, then you could say: ‘OK, we need more targeted intervention.’”

Much of the concern lies in how the data will be anonymised. Campaigners note that it is frequently possible to isolate individuals in mass releases of location data: in 2014, when New York City released a dataset of 173m individual taxi trips, for instance, researchers rapidly uncovered that it was “trivial” to track down individual drivers and observe their working days, calculate their income, or even infer where they live.

But Cheshire said the data the government received was unlikely to be so in-depth. Instead, the most useful information for tracking aggregate movements is the level of demand at any given mast, which can’t be reverse-engineered to breach privacy. If the government went any further, he said, “ensuring that there are checks and balances – privacy, consent and ethics – becomes fundamental”.

An O2 spokesperson said: “Using our mobile technology, we have the potential to build models that help to predict broadly how the virus might move. This would in no way be able to identify or map individuals, and operates within strict privacy guidelines.”

[ Original @ the Guardian ]