In this paper, we discuss the proliferation of household smart devices and review the literature to explore whether the implementation characteristics of such systems may provide avenues of attack to obtain private biometric data. Examples include the use of mechanical hard drives as audio microphones and interception of soft-keyboard input through audio analysis of haptic feedback. As the use of biometric data increases in casual environments, the opportunity for it to be stolen in unexpected ways is also increasing. There are many examples of the technology being utilised by hackers to enable unexpected use such as spoofing. We examine the importance and sanctity of biometric data in the modern world and posit that manufacturers must avoid complacency and advocate secure design, to ensure security and privacy of users.