> If the software to watermark is widely available (as it appears to be) then an adversary has all they need to corrupt any existing watermark.
The commercial software used to embed watermarks into the digital files is not readily available. It’s also much more advanced than putting an obvious logo on screen. There are techniques to embed signals into the video that survive some amount of compression and aren’t obvious to the viewer.
You can identify signals deep below the noise floor if they’re sufficiently low bandwidth and you know what you’re searching for. See GPS and its ability to work even though the signal is completely lost in the noise until you know what you’re searching for in the noise.
The commercial software used to embed watermarks into the digital files is not readily available. It’s also much more advanced than putting an obvious logo on screen. There are techniques to embed signals into the video that survive some amount of compression and aren’t obvious to the viewer.
You can identify signals deep below the noise floor if they’re sufficiently low bandwidth and you know what you’re searching for. See GPS and its ability to work even though the signal is completely lost in the noise until you know what you’re searching for in the noise.