Over 212,000 people have signed a SumOfUs.org petition calling on the government and NHS England to think again about selling access to our personal medical information to private companies.

Our members are very worried about the government’s proposed collection and sale of patient data held by GPs. They are deeply concerned about who will have access to the data, about others seeking to make money from their medical histories, and about protecting their privacy.

Let me be clear, we are not arguing that these data should not be used for medical research purposes. What our members are asking is that open season isn’t declared on their private medical information—at least not in the way it is currently proposed. What may have started with the best of intentions to improve patient care, has rapidly degenerated into an attempt to monetise our medical records.

Governments make lots of promises that later turn out to not be true, especially when it comes to how our personal data are used. We’ve recently seen how the intelligence agencies have arguably been misusing our personal data on an epic scale. Every email we write, every phone call we make, every website we visit, is logged, scanned, and stored by a variety of companies and government agencies. What is particularly disturbing about the care.data proposals as they stand, is that the government is proposing to extend this new world to the consultation room.

The government argues that all personal identifiers will be removed from the saleable records. This may be true, but it doesn’t take a genius to use other publicly available data like DVLA records, credit files, and the electoral register to easily identify people and their medical conditions. Whatever the assurances are from the government, they aren’t enough. Our data won’t be as safe, and won’t be as secure, as the government and NHS England wants us to believe. The only way to mitigate corporate misuse of our data is to prevent anyone not conducting medical research from having access to the data in the first place.

Imagine the implications for individuals if insurance companies seek to match up data with their own? Perhaps banks will seek to use the information to deny people long term credit such as mortgages? Or maybe personal injury lawyers will want to use the data to help them identify people who’ve had serious accidents? That’s the big problem with the proposals as they stand, by making data open to private companies—no one is sure exactly how they will be used and by whom.

It doesn’t get much more personal than the conversations we have with our family doctors. They often know some of the most private details about our lives—maybe you had abortion, maybe you are struggling with drug or alcohol problems, or maybe you have a disease with a heavy stigma associated with it. We all probably have things in our files that we don’t really want the world to know about. But under the proposed system, whatever is in our records will be publically available for anyone with the cash to buy it.

It is true that patients can opt out. But the government isn’t exactly making this easy for patients, their doctors, practice managers, and receptionists. The current advice is to phone up your practice and opt out over the phone. Not only does this make the barriers to opting out quite high, it places the burden of dealing with the new system firmly on hard pressed general practices.

There is a clear way forward for the government and the whizzes that dreamt up the new system—that is to not sell access to personal medical information to anyone not conducting medical research. Unless the government is determined to make a fast buck from our medical histories this is a very realistic way to make the system better, restore trust, and potentially improve health outcomes for millions of people.

Competing interests: I declare that I have read and understood the BMJ group policy on declaration of interests and I hereby declare the following interests: I’m employed by SumOfUs.org who are running a campaign to stop the sale of GP patient data on the open market.

Martin Caldwell is a campaigner with the online campaign group SumOfUs.org