Analysis of 22,484 pornography websites indicated that 93% leak user data to a third party; tracking on these sites is highly concentrated by Google, Oracle and Facebook

Tracking sex: The implications of widespread sexual data leakage and tracking on porn websites. Elena Maris, Timothy Libert, Jennifer Henrichsen. arXiv, Jul 15 2019. https://arxiv.org/abs/1907.06520

Abstract: This paper explores tracking and privacy risks on pornography websites. Our analysis of 22,484 pornography websites indicated that 93% leak user data to a third party. Tracking on these sites is highly concentrated by a handful of major companies, which we identify. We successfully extracted privacy policies for 3,856 sites, 17% of the total. The policies were written such that one might need a two-year college education to understand them. Our content analysis of the sample's domains indicated 44.97% of them expose or suggest a specific gender/sexual identity or interest likely to be linked to the user. We identify three core implications of the quantitative results: 1) the unique/elevated risks of porn data leakage versus other types of data, 2) the particular risks/impact for vulnerable populations, and 3) the complications