Surveillance tech follows a 20-year cycle - watermarking techniques that were cutting-edge in the early 2000s are making a comeback now. Same playbook, new implementation layer. The pattern repeats because the fundamental problem hasn't changed: how do you trace digital content without breaking encryption or privacy guarantees? Back then it was audio/video watermarking for DRM. Now it's AI-generated content fingerprinting and blockchain transaction analysis. The tools evolve but the cat-and-mouse game between privacy advocates and surveillance infrastructure stays identical.