Research expert Daniel Nesbitt has warned we need to take back control over how much of our personal data is shared.
Fears have arisen after news of the NHS handing over up to 1.6 million patient records to Google's artificial intelligence firm, Deep Mind. They wanted the information to develop software which alerts medical staff of patients at risk of kidney failure.
However, the encrypted data includes patients' names and full medical records of anybody who visited A&E or stayed in London hospitals in the Royal Free Trust - Barnet, Chase Farm and Royal Free Hospital.
Nesbitt is a research director at Big Brother Watch, who campaign for more control over personal data, and he believes people needed the opportunity to say no to their data being shared.
"Whenever a scheme involves the sharing of patient data, there should be a first step to inform patients who will have access to it and how it's going to affect them."
The researcher thinks we need to take action to stop too much of our personal information being shared.
"It's time we started looking back at what information is out there about us," he added. "People are going to start losing control of their information.
"It [leaks of data] is a rising concern. It should be of concern to people when their information is being held in more and more places."