When NSA contractor Reality Winner allegedly printed out a trove of top secret government information, little did she know that a hidden feature within the printer called tracking dots could forensically lead authorities straight back to her.
What you may not know is that most laser printers made today, found everywhere from offices to public libraries, all have the same tracking technology. So, is your printer able to track you?
Below is a list of printer manufacturers the non-profit digital privacy organisation, EFF (Electronic Frontier Foundation), has put together to show which are using invisible yellow dot forensic technology to give away location, time, date, serial number and user ID every time they are used.
Major brands from Canon to Xerox all feature on the lengthy list.
What are yellow tracking dots?
Some printers (as listed above) will secretly print a pattern of yellow dots in the background of any document a user prints off. These dots are invisible to the naked eye but when put under a microscope or blue light, they will appear. The unique pattern of dots are put through a deciphering tool to disclose information about where and when the document came from, but you wouldn't even know they were there.
The EFF claims "it is probably safest to assume that all modern colour laser printers do include some form of tracking information". Following an freedom of information request, the EFF was given a number of documents that suggested "all major manufacturers entered a secret agreement with governments to ensure that the output of those printers is forensically traceable".
Its list of manufacturers using yellow dot tracking was created by looking at printed documents under blue light or microscope, printer manuals and manufacturer statements. It also included statements from technicians and sellers.
It states that documents printed on non-laser printers may not be subject to the same yellow dot tracking system but did not rule out other forms of hidden forensic tracking that it is currently unaware of.