Activity-tracking wearables and apps can be hacked with nothing more than a credit card-sized Raspberry Pi computer and a few retail components, according to security firm Symantec.
Scanners taken to busy public locations in Ireland and Switzerland, as well as major sporting events, were found to be able to intercept numerous signals from the wearable devices even when running on passive mode, thus posing a security risk to those who use them.
Symantec said: "In our testing, we found that all the devices we encountered can be easily tracked using the unique hardware address that they transmit."
More than half of the activity tracking apps examined by the firm did not have privacy policies, with a fifth sending out login details in plain text, potentially exposing users to identify theft through sensitive data stored on the software.
Activity-tracking apps often contact domains so that information can be accessed later from a different device, with the apps examined by the firm liaising with an average of five.
"For convenience, many manufacturers use Bluetooth Low Energy to allow the device to wirelessly sync data to a smartphone or computer," Symantec added.
"However, this convenience comes with a price: the device may be giving away information that can allow it to be tracked from one location to another."