Investigating Bystander Privacy in Chinese Smart Home Apps

TL;DR

This study examines privacy practices in Chinese smart home apps, revealing gaps between policies and actual data handling, with a focus on the lack of bystander privacy protections and transparency issues.

Contribution

It provides a comprehensive analysis of Chinese smart home apps, highlighting privacy gaps and proposing design improvements to enhance bystander privacy and transparency.

Findings

Most apps comply with regulations but have implementation gaps.

Bystander privacy is largely overlooked in policies and UI.

Discrepancies exist between privacy labels and actual data practices.

Abstract

Bystander privacy in smart homes has been widely studied in Western contexts, yet it remains underexplored in non-Western countries such as China. In this study, we analyze 49 Chinese smart home apps using a mixed-methods approach, including privacy policy review, UX/UI evaluation, and assessment of Apple App Store privacy labels. While most apps nominally comply with national regulations, we identify significant gaps between written policies and actual implementation. Our traceability analysis highlights inconsistencies in data controls and a lack of transparency in data-sharing practices. Crucially, bystander privacy -- particularly for visitors and non-user individuals -- is largely absent from both policy documents and interface design. Additionally, discrepancies between privacy labels and actual data practices threaten user trust and undermine informed consent. We provide design recommendations to strengthen bystander protections, improve privacy-oriented UI transparency, and enhance the credibility of privacy labels, supporting the development of inclusive smart home ecosystems in non-Western contexts.