Explore a comprehensive security analysis of Facebook's U.S. Ad Library in this 17-minute IEEE conference talk. Delve into methodologies for detecting weaknesses in political advertising transparency, including ways malicious advertisers can avoid accurate disclosure. Learn about a proposed clustering-based method for identifying undeclared coordinated activity, which uncovered 16 clusters of likely inauthentic communities spending over $4 million on political ads. Gain insights into the potential of transparency as a tool for combating disinformation and discover recommendations for improving advertising transparency security on Facebook and other platforms.