Privacy Lost and Found: An Investigation at Scale of Web Privacy Policy Availability

Legal jurisdictions around the world require organisations to post privacy policies on their websites. However, in spite of laws such as GDPR and CCPA reinforcing this requirement, organisations sometimes do not comply, and a variety of semi-compliant failure modes exist. To investigate the landscape of web privacy policies, we crawl the privacy policies from 7 million organisation websites with the goal of identifying when policies are unavailable. We conduct a large-scale investigation of the availability of privacy policies and identify potential reasons for unavailability such as dead links, documents with empty content, documents that consist solely of placeholder text, and documents unavailable in the specific languages offered by their respective websites. We estimate the frequencies of these failure modes and the overall unavailability of privacy policies on the web and find that privacy policies URLs are only available in 34% of websites. Further, 1.37% of these URLs are broken links and 1.23% of the valid links lead to pages without a policy. Further, to enable investigation of privacy policies at scale, we use the capture-recapture technique to estimate the total number of English language privacy policies on the web and the distribution of these documents across top level domains and sectors of commerce. We estimate the lower bound on the number of English language privacy policies to be around 3 million. Finally, we release the CoLIPPs Corpus containing around 600k policies and their metadata consisting of policy URL, length, readability, sector of commerce, and policy crawl date.