> The methods presented in this paper have many applications in law enforcement such as tracking, counterfeiting, and child pornography. The downside is that th

> The methods presented in this paper have many applications in law enforcement such as tracking, counterfeiting, and child pornography. The downside is that they provide a mechanism for a simple device, a printer or a digital camera, to spy on its user. A typical user cannot turn off these signatures, particularly the intrinsic signature, without very detailed knowledge of how the device operates. This could have dire consequences for many important uses of these devices in our society. For example a whistleblower who would like to share documents with a regulatory agency could be in danger in that their printer could be identified as the one that produced the documents. [1] Prophetic words from a 2008 paper (PDF) [1]. This paper may be duplicate information, but reading this paper impressed upon me how many more ways there may be to spy on people than I could imagine (and I know about some existing things like side-channel attacks... how do I spy on thee? Let me count the ways.) So don't register your printer with the manufacturer, folks; the serial number may be on every page it prints. Ditto for digital cameras. Then again, is fighting for digital privacy a losing battle when at every turn, there are deliberately hidden bits of PII? Pun intended. [1]: https://engineering.purdue.edu/~prints/public/papers/sp_article_09_chiang.pdf https://engineering.purdue.edu/~prints/public/papers/sp_arti...