A new term, "spymark," describes hidden signals embedded in digital media to trace content without user consent. Google’s Synth ID can embed a 136-bit payload in a 512x512 image, encoding identifiers linked to personal data. Similar systems are being developed by OpenAI and other firms, moving beyond traditional watermarks into robust tracking.

These spymarks can alter images, audio, and video imperceptibly, raising privacy concerns. The article argues that renaming the technology clarifies its surveillance nature, distinguishing benign watermarks from invasive tracking, and urges clearer terminology to focus discussion on privacy risks.