Last March, Stanford University designed an app to study cardiovascular disease. Using Apple’s open-source ResearchKit platform, a whopping 11,000 participants signed up in less than a day.

“To get 10,000 people enrolled in a medical study, normally it would take a year and 50 medical centers around the country,” said Dr. Alan Yeung, medical director of Stanford Cardiovascular Health. “That’s the power of the phone.”

The mobile phone is powerful indeed, which is why two Big Pharma giants, GlaxoSmithKline (GSK) and Purdue Pharma, have their sights set on ResearchKit. It’s one thing for researchers at Stanford to study disease, but it’s quite another for Big Pharma—an industry with questionable ethical history. These companies already spend billions of dollars to market their drugs—how much more effective would those campaigns be if they can track your every move?

In 2012, GlaxoSmithKline paid out the largest health care fraud settlement in U.S. history, totaling $3 billion for promoting the anti-depressant Paxil to children under 18. According to the Department of Justice, charges against GSK also include the failure to report certain safety data and alleged false price reporting practices.

The world’s sixth-largest pharmaceutical company, GSK told The Daily Beast, “While we already have many biotelemetry studies underway, we are currently working on integrating ResearchKit into clinical trials and planning to start in coming months.”

The company is in the early stages of looking into ResearchKit and was unwilling to divulge specific plans. But Mary Rhyne, a GSK spokeswoman, told me that company sees ResearchKit as potentially improving “patient engagement and data collection” efforts.

Purdue Pharma, on the other hand, paid over $600 million in criminal fines for misleading regulators, doctors, and patients on the addictive risks of its notorious painkiller, OxyContin. Purdue has been entangled in another, separate civil lawsuit with the State of Kentucky, which alleges the pharmaceutical behemoth is responsible for causing a statewide opiate epidemic.

Since the unveiling of ResearchKit last March, it’s been mostly nonprofits, medical institutions, and universities using the platform. This would be the first instance of for-profit companies considering ResearchKit for commercial purposes.

Larry Pickett Jr., Purdue’s vice president and chief information officer, told BuzzFeed News that if Purdue pursues a ResearchKit app, it will be made explicit to consumers that their data would be used for marketing new drugs. The interest of drug companies should come as no surprise for several reasons—the main one being cost. Rhyne of GSK told The Daily Beast that, “mobile technologies hold great potential for reducing cost.” Putting a new pharmaceutical drug to market runs close to $2.6 billion, according to Tufts Center for the Study of Drug Development. In 2012, Forbes reported GSK was spending roughly $8 billion on R&D per drug.

Another advantage of ResearchKit is the unprecedented ability to acquire data at never before seen rates, as seen in Stanford’s cardiovascular study. Data, collected by self-report questionnaires or your phones motion sensors, will beam back a real-time profile of a participant’s functioning. This cuts out lengthy hospital visits that traditionally require high dollar incentives to keep people involved in clinical trials. With ResearchKit, investigators can capture your every step from miles away.

Does Apple have any say in regards to who uses their software and for what purpose it is being used? No.

“We’ve made ResearchKit open-source so Apple won’t even control who uses it,” Apple’s senior vice president of operations Jeff Williams told BuzzFeed News in an interview last month.

“We will control what we put on our App Store, but we won’t control who uses it. And so I think the promise of using ResearchKit for development of drugs—if they’re lifesaving, I think that’s a positive thing,” Williams said.

Many have criticized the reliability of the samples ResearchKit will generate. The average iPhone user has a higher education and income than the average Android user, according to CivicScience Inc. Such demographic disparities may result in biased sampling.

C. Michael Gibson, a professor at Harvard Medical School, raised another good point: What if you lend someone your phone? The data being recorded and transmitted to the investigators may not be from whom they think it is.

For now, anyone can use ResearchKit if they agree to abide by guidelines laid out for human subjects research, said an Apple spokesperson. These include consent from participants, clear statement of purposes so participants know what they’re signing up for, and approval from an independent ethics review board. If a study violates any of these the app will be rejected. When I asked the interested companies what kind of incentives one can expect for participating in a clinical trial, neither company had an answer.

The more a company knows about your habits, the more power they have over you. So should Big Pharma, with its drive for profit and problematic track record, be allowed access to this intimate form of power?