If you test positive for COVID-19, a contact tracer will call to find out who you interacted with since 48 hours before you felt sick. Some people, though, want the phones themselves to help with the work.
At a news conference earlier this month, Allegheny County Health Department Director Debra Bogen said her agency is considering how smartphone apps could help to investigate cases.
“We have looked at a variety of options, and I think we’re all sort of learning what those options are,” Bogen said. “The problem is that there are many. And there are privacy issues.”
Experts say communities must expand their capacity to test, trace and isolate COVID-19 cases before they can safely resume daily life amid the coronavirus pandemic. Contact tracing apps, meanwhile, are credited with helping to contain the coronavirus in some countries.
The programs start by tracking location, Bluetooth, or other data stored in cell phones. If the data suggests an app user has interacted with an infected patient, the user gets a notification. Contact tracers could also draw on the same information to chase down other likely contacts, and tell them to quarantine or get tested.
But there are concerns the technology reveals too much about users – and yet also not enough.
Public health v. privacy rights
Dierdre Mulligan, a professor in the School of Information at the University of California, Berkeley, said the law allows some privacy rights to be eroded when officials need to respond to a public-health crisis.
“And we’re actually going to make decisions that might intrude on your privacy,” Mulligan said, “because we understand that we’re all in this together.”
After all, contracting the coronavirus doesn’t just risk the well-being of infected people, but also that of anyone they come into contact with. So, the detective work involved in contact tracing itself, and the collection of confidential information in public health databases is legal, Mulligan said.
But she added that privacy rights do come into play when phones proactively track and record individuals’ contacts before they've been infected.
Mulligan and others say that contact tracing technology poses legitimate privacy threats. Some worry, for example, that employers will require workers to use contact tracing software, while others dread the potential for hacking.
Mulligan noted that some fear police could use the technology to target people who have interacted with a criminal suspect.
“People have already suggested, ‘Well, wouldn’t [U.S. Immigration and Customs Enforcement] like to know that?’ because they’d be able to identify other people who might be illegally in the country," she added. "You can imagine lots of ways in which there could be pressure to repurpose the system that’s being built.”
While some countries mandate the use of contact-tracing apps, Mary Catherine Roper, Deputy Legal Director for the American Civil Liberties Union of Pennsylvania, said in the U.S., participation must be voluntary.
“In our country, we don’t allow the government to conduct mass surveillance on us,” Roper said. “The Constitution doesn’t permit that. Our culture doesn’t permit that.”
In fact, the U.S. Supreme Court ruled in 2018 that the Fourth Amendment bars law enforcement from accessing cell phone location data without a search warrant.
Roper said when contact tracing apps are voluntary, the companies and governments that sponsor them must spell out exactly what participants are signing up for.
“What reasonably could you have thought you were agreeing to? And what precautions have been taken to make sure that this data is not used in ways beyond what you thought you were agreeing to?” the ACLU lawyer said, listing the types of questions that app use policies should answer.
'Not a perfect science'
Jennifer King, who serves as Director of Consumer Privacy for Stanford Law School’s Center for Internet and Society, noted that such terms of service often are “very non-transparent” and could make it difficult for users to make an informed choice about whether to opt in to contact tracing.
App developers in the U.S. have made a point to adopt privacy safeguards. For example, researchers at Carnegie Mellon University built a program that alerts users if they’ve come close to someone who has the disease, while also keeping participants anonymous and not reporting the alerts to anyone else.
Google and Apple, meanwhile, are teaming up to establish a system that will only share coronavirus data with public health agencies and only until the end of the pandemic.
Carnegie Mellon computer science professor Jason Hong noted that while privacy protections are essential, they limit public health benefits. In other countries like China and South Korea, governments have used a host of data sources, including GPS and credit card records, to pinpoint locations. But in the U.S., apps rely on less precise technology.
“If you are on the opposite side of a building from a person, or even on a different floor, and you never really met this person, you could still be having false positives that you’re actually close to them,” Hong said, describing one shortcoming with the Bluetooth signals that apps in the U.S. are expected to rely on.
King added that the technology won’t work if users don’t have their Bluetooth and location services turned on, or if they simply don’t have their phones with them.
“This is not a perfect science … at all,” she added. “It’s just a way potentially to try to identify the gaps that as humans we may have trouble trying to remember or put together.”
Kathleen Carley, a computer science professor at Carnegie Mellon, said that on balance, those possible benefits make the apps worth adopting. She thinks they would help contact tracers to do their jobs.
“The contact apps get rid of a lot of that guesswork and would actually make it much safer for people,” Carley said. “I personally think it’s a great idea, and that we should be doing it.”
Not everyone agrees: Polls show that at most, only about half of Americans are open to downloading contact tracing software. That might be a problem, because experts say 60 percent of the population must opt in for the apps to have an impact.