Please see revised start time for Ryan Amos's Pre FPO talk today. Ryan Amos will present his Pre FPO "Consumer protection with longitudinal data collection and analysis" on Thursday, April 1, 2021 at 2pm via Zoom. Zoom link: [ https://princeton.zoom.us/j/98956078851?pwd=UWxReS9DcWc3aFlTWEFydTJTVXlnQT09 | https://princeton.zoom.us/j/98956078851?pwd=UWxReS9DcWc3aFlTWEFydTJTVXlnQT09 ] Committee: Examiners: Prateek Mittal (adviser), Ed Felten (adviser), Arvind Narayanan Readers: Jonathan Mayer, Joe Calandrino ( Federal Trade Commission) All are welcome to attend. Title: Consumer protection with longitudinal data collection and analysis Abstract: We'll discuss how we can use longitudinal data to understand issues surrounding consumer protection, particularly issues driven by misaligned incentives in advertising. In the first half, I'll present our work on collecting and analyzing our dataset of one million privacy policies from a twenty year timespan. Our work adds to the growing body demonstrating the inadequacy of the notice-and-choice model of privacy policy regulation. We find that privacy policies have become more difficult to read, and, by comparing our findings to prior web measurements, that they show a troubling lack of transparency. Our work helps contextualize the impact of the GDPR by showing how it stands out against a decade of privacy policy changes. In the second half, I'll present our ongoing work on collecting and analyzing a dataset of Yelp's review recommendation system, which we take as a proxy for fake review filtering. To understand the evolving game between fake reviewers and platforms, we frame our work differently from prior work -- rather than focusing on the reviews themselves, we focus on the platform's reactions to reviews. We find that a substantial proportion of filtered-out reviews are later reclassified, suggesting that Yelp takes an aggressive approach to removing reviews. I'll additionally discuss our ongoing work in this field and questions we want to answer.