The Writing on the Wall and 3D Digital Twins: Personal Information in (not so) Private Real Estate

Online real estate companies are starting to offer 3D virtual tours of homes (3D digital twins). We qualitatively analyzed 44 3D home tours with personal artifacts visible on Zillow and assessed each home for the extent and type of personal information shared. Using a codebook we created, we analyzed three categories of personal information in each home: government-provided guidance of what not to share on the internet, identity information, and behavioral information. Our analysis unearthed a wide variety of sensitive information across all homes, including names, hobbies, employment and education history, product preferences (e.g., pantry items, types of cigarettes), medications, credit card numbers, passwords, and more. Based on our analysis, residents both employed privacy protections and had privacy oversights. We identify potential adversaries that might use 3D tour information, highlight additional sensitive sources of indoor space information, and discuss future tools and policy changes that could address these issues.