ArtCraft founder urges 'spymarks' label for hidden AI tracking signals
Brandon Thomas says invisible signals like Google's SynthID can survive editing and link content to users, and should not be called watermarks.
ArtCraft founder Brandon Thomas published an article on November 8, 2026 arguing that invisible tracking signals embedded in digital content should be called "spymarks" rather than watermarks, citing the privacy risks they carry. ArtCraft develops AI-based image and video creation software.
According to gigazine.net, Thomas defines spymarks as invisible tracking signals placed in physical or digital media that can record how content is used without the user's knowledge or consent. Google's SynthID, for example, embeds hidden signals in images, audio, text and video that people cannot perceive.
In images, the signals are written into the frequency domain rather than into visible pixels. Thomas notes that SynthID-O, the image variant of SynthID, can store a 64-bit database identifier plus 72 error-correction bits inside a 512x512 pixel image. Such data can include a database ID linked to a user.
Because the signal sits deep in the media rather than in metadata, it may survive file editing and the removal of metadata such as EXIF or ID3 tags, Thomas writes. He adds that OpenAI and many other technology companies are also building spymark systems to identify AI-generated content.
Thomas says the risk is greatest for whistleblowers and for people who do not want to be persecuted for their statements or affiliations, and compares the situation to the surveillance society depicted in Orwell's 1984.
Watermark or spymark?
The word watermark has historically described benign uses such as proving authenticity, security features on banknotes and copyright notices, according to the article's background discussion.
Quick answers
What is a spymark?
It is the term Brandon Thomas uses for invisible tracking signals embedded in physical or digital media that can track how content is used without the user's knowledge or consent.
How do spymarks differ from metadata?
Unlike EXIF or ID3 metadata, spymark signals are buried deep in the media and may survive file editing and metadata removal, according to Thomas.