Described herein are techniques for preventing software applications from gaining access to unauthorized biometric data in accordance with user preferences. In some embodiments, a software application requests access to sensor data collected by a sensor installed on a user device via a gateway application installed on the user device. Upon receipt of the request, the gateway application determines what types of biometric data the software application is authorized to obtain within the sensor data. The gateway application then identifies biometric data that is present within the sensor data. The sensor data is then altered such that biometric data that the software application is not authorized to obtain is obfuscated. Once the sensor data has been altered, the software application is provided access to that altered sensor data.