From FitBit...
INFORMATION WE RECEIVE FROM YOUR USE OF OUR SERVICES DEVICE INFORMATION
Your device collects data to estimate a variety of metrics like the number of steps you take, your distance traveled, calories burned, weight, heart rate, sleep stages, active minutes, and location. The data collected varies depending on which device you use. Learn more about the features of
our various devices and how you can use
MobileTrack. When your device syncs with our applications or software, data recorded on your device is transferred from your device to our servers.
LOCATION INFORMATION
The Services include features that use precise location data, including GPS signals, device sensors, Wi-Fi access points, and cell tower IDs. We collect this type of data if you grant us access to your location. You can always remove our access using your Fitbit device or mobile device settings. We may also derive your approximate location from your IP address.
USAGE INFORMATION
When you access or use our Services, we receive certain usage data. This includes information about your interaction with the Services, for example, when you view or search content, install applications or software, create or log into your account, pair your device to your account, or open or interact with an application on your Fitbit device.
We also collect data about the devices and computers you use to access the Services, including IP addresses, browser type, language, operating system, Fitbit or mobile device information (including device and application identifiers), the referring web page, pages visited, location (depending on the permissions you have granted us), and cookie information.
Fitbit Legal - Privacy Policy