The U.S. House Oversight Committee is probing a collection of period tracking apps and data brokers in light of emerging concerns about how private health data might be weaponized in the dawning post-Roe v. Wade era.

The committee issued letters today to data brokers SafeGraph, Babel Street, Digital Envoy, Placer.ai and Gravy Analytics and app makers Flo Health, Glow, GP International, Clue developer BioWink, and Digitalchemy Ventures.

In the letters, the representatives requested information on the companies’ data collection and retention policies “including documents and communications concerning the actual or potential production of such data to external entities voluntarily or subject to legal obligation, such as a subpoena.” The lawmakers also asked for information explaining each company’s data sharing practices and how much revenue and profit those companies have made off that data going back five years.

“The collection of sensitive data could pose serious threats to those seeking reproductive care as well as to providers of such care, not only by facilitating intrusive government surveillance, but also by putting people at risk of harassment, intimidation, and even violence,” the committee wrote.

“Geographic data collected by mobile phones may be used to locate people seeking care at clinics, and search and chat history referring to clinics or medication create digital bread crumbs revealing interest in an abortion.”

The probe is spearheaded by Chairwoman Rep. Carolyn Maloney, Subcommittee on Economic and Consumer Policy Chairman Raja Krishnamoorthi and Rep. Sara Jacobs. The lawmakers have set a July 22 deadline for the companies to comply with the requests.

With Roe repealed and abortion no longer a protected federal right in the U.S., privacy advocates, lawmakers and consumers alike have raised concerns that location and health-tracking data may be turned against people seeking abortions in the U.S.

Both kinds of data paint a very personalized picture of an individual’s behavior. Health and period-focused apps can track missed periods and fertility cycles, while user location data bought and sold by shadowy data companies can provide precise location information that could implicate anyone who visits an abortion provider.

The White House mentioned its own concerns about digital surveillance and companies that collect or sell “sensitive health-related data” Friday in a new executive order focused on protecting access to abortion.

Last week Google announced that it would erase location tracking data for “particularly personal” places, including abortion and fertility centers. In May, Congressional Democrats wrote a letter to Google CEO Sundar Pichai urging the company to extend new privacy measures in light of the looming reversal of Roe v. Wade.

Consumers are also taking matters into their own hands, swapping their current period trackers for alternative apps that they perceive to be safer, though in some cases they might be jumping out of the frying pan and into the fire.