Explore the critical issue of user data retention after account deletion in mobile applications through this 18-minute IEEE conference talk. Delve into the research methodology, including the categorization of data types, tool chain development, and analysis techniques used to identify leftover account information. Learn about the Account Deletion Analyzer, which finds deletion strings and listeners, and the Leftover Account Analyzer's high-level approach. Examine the Leftover Account Cleaner and its effectiveness. Gain insights into evaluation results and efficiency metrics, concluding with a Q&A session to address lingering concerns about data privacy and security in mobile app ecosystems.