Explore the fingerprintability of browser extensions in this IEEE Symposium on Security & Privacy presentation. Delve into the XHOUND system, an automated tool for fingerprinting browser extensions, and its application to 10,000 popular Google Chrome extensions. Examine how an extension's activity in a page's DOM can reveal its presence, and understand the implications for user privacy. Learn about the survey conducted on users' installed extensions and the potential for unique identification. Discover the proof-of-concept extension-fingerprinting script developed from XHOUND's results, demonstrating how trackers can fingerprint multiple extensions rapidly. Consider the intrusive nature of extension-based fingerprinting compared to other browser and system properties, and explore potential defense strategies against this tracking method.