There must not be a hidden purpose or something I as a citizen don’t know,” she says. “The main thing is people entering such a system know what they are doing.

Under pressure from privacy activists, the scientific community has created a body called the Pan-European Privacy-Preserving Proximity Tracing coalition in Switzerland, led by Germany’s Fraunhofer Heinrich Hertz Institute, to create standards for apps being developed that adhere to European laws around privacy.

The data drawn from such apps can both track individual sufferers and people they have encountered via contract tracing methods to create a much deeper data set for governments. 

The telecoms industry has had to tread a fine line on the use of data or face punitive action. In the US, the Federal Communications Commission last month fined the four largest industry players a combined $208m over the historic sale of location data to third parties without the explicit consent of users

However, he says there are apps that help citizens choose which data they share, leading to a more efficient tracking of the virus. “If people can decide themselves if they want to participate or not, then we have privacy-friendly alternatives. That’s a game changer.”Some analysts worry that the data sets could be put to other uses in the future. 

The concerns about political use of data have been aggravated by the fact that the European Commission wants the telecoms companies to provide the actual aggregated data, not just access to insights from that information

Still, assurances from officials and industry executives have done little to appease anxiety that privacy rights could be brushed aside as governments seek to use tools of mass surveillance in their efforts to combat the virus.

The insights that telecoms companies can derive from these data sets build on their experience of working with epidemiologists to track infectious diseases in the developing world.

“The use of technology should end as soon as the health of the people is guaranteed. We must be vigilant,” he says. “If you go to one extreme, you’ll have super high privacy but then you die and it becomes useless to have privacy. It’s a very delicate balance to reach.”

But he says it is a tricky balance to strike between using technology to help tackle health crises and safeguarding privacy. 

China and Israel have also used personal telecoms data to trace coronavirus patients and their contacts. Governments around the world are creating apps to gather more personal data, such as who is sick and with whom they have been in contact.

But the use of such data to track the virus has triggered fears of growing surveillance, including questions about how the data might be used once the crisis is over and whether such data sets are ever truly anonymous. 

Mapping how populations move between locations has proved invaluable in tracking and responding to epidemics

the best way to track the spread of the pandemic is to use heatmaps built on data of multiple phones which, if overlaid with medical data, can predict how the virus will spread and determine whether government measures are working.

The strategies for reopening an economy before a vaccine is developed could involve monitoring the contacts of newly infected people, which will raise questions about how much curtailment of privacy societies are prepared to take

“Diseases don’t respect national borders,” says Andy Tatem, an epidemiologist at Southampton who has worked with Vodafone in Africa. “Understanding how diseases and pathogens flow through populations using mobile phone data is vital.”