Deleting your period tracking app won’t keep your health data private, says information security expert Anton Dahbura.

As soon as news leaked in May of the possible reversal of Roe v. Wade, a drumbeat began on social media: Delete your period trackers.

“I’m concerned that people will be lulled into a false sense of security if they’re led to believe that their phone itself is somehow safe.”

With abortion rights under threat, new fears arose that the health data stored on such apps, which track fertility and menstrual cycles, could be used as evidence of criminal activity in states where abortions could be outlawed.

With the United States Supreme Court’s subsequent ruling on June 24, the calls for data security have intensified, and a number of app developers and tech companies have upped their privacy protections in response. The issue has the attention of the US House of Representatives, where a new bill called “My Body, My Data” is circulating, and one panel is investigating tech companies’ practices. An executive order President Joe Biden signed Friday aimed at protecting abortion access also seeks to shore up digital privacy.

Data security experts warn, however, that this issue runs deeper than any app. “The underlying risk is that a person’s phone—the phone itself, not necessarily individual apps or web browsers—maintain a significant amount of data even when apps are deleted,” says Dahbura, executive director of the Johns Hopkins University Information Security Institute.

“I’m concerned that people will be lulled into a false sense of security if they’re led to believe that their phone itself is somehow safe.”

And it’s not only phones, he says—it’s any tablet, computer, smartwatch, or digital assistant. “If a law enforcement agency has access to a person’s devices, including data that’s supposedly been deleted, the information that can be harvested is likely to be overwhelming.”

Here, Dahbura offers more insight on the vulnerabilities of reproductive health data in an age where terminating a pregnancy constitutes a crime in parts of the country: