This talk is part of a two-presentation session running from 2:50 PM - 3:40 PM. The session will feature two presentations back-to-back, with Q&A after each presentation.

We present findings from numerous interviews with CyberTipline stakeholders: law enforcement, platforms, the National Center for Missing and Exploited Children (NCMEC), and civil society. Our findings, to be published in April, offer a better understanding of stakeholders’ constraints and behavior. We find law enforcement cannot accurately triage CyberTipline reports, for multiple reasons including: platforms’ inconsistent/inaccurate report completion; inefficiencies in processing reports about memes; legal constraints on NCMEC’s and law enforcement’s ability to view reported files and communicate best practices to platforms; and opportunities for improved technical staffing and infrastructure at NCMEC. We conclude with policy recommendations. For platforms, those include: strategies for effective communication with NCMEC and law enforcement; dedicating engineering resources to deploying and optimizing hash-based detection tools and implementing NCMEC’s reporting API; ensuring an accurate, automated process for completing all relevant report fields; auditing report quality for accuracy and consistency; and considerations for human review of reported files.