In today’s surveillance-obsessed digital world, we should all be concerned about the erosion of our civil liberties and basic human rights. Is your printer spying on you? It’s not as crazy of a question as it might have seemed. There are many examples of authoritarian governments using shady tactics to spy on their own citizens and detain them but these authoritarian tendencies are not restricted to foreign powers, could it be tech companies and the corporations that build printers are spying on you, too?

Why Does it Matter?

We should certainly heed the lessons of human history but all too often we are unaware of the warning signs of changes within society that could indicate a move to an authoritarian regime. And sadly, it seems that too many of us are prone to forget the lessons of history or simply see them as something irrelevant to our modern world.

In short, the erosion of our freedoms matters because this sets a precedent that can easily lead to centralized control and widespread social engineering that results in the kind of society that does not value human freedom at all.

Even though we are aware that government agencies and even private companies are using our data, collecting it, and analyzing it at some level, we are still often surprised at the level of sophistication of these shadowy techniques. In this context, the very idea that the humble printers in our offices and homes could be spying on us seems crazy until the details are known.

The NSA Connection

Since revelations from U.S.-based whistle-blowers that the National Security Agency (NSA) has been actively spying on citizens through hardware backdoors and other methods, we have all become a lot more paranoid and with good reason.

In 2017, the FBI arrested a government contractor on the basis of printing and leaking an important document to the media. What was most interesting about the case was not the arrest itself but the fact that the FBI seemed to be able to pinpoint where and when the leaked documents were printed.

Experts analyzed the leaked document and found something curious on the paper: a series of small yellow dots in a pattern that was barely visible to the naked eye. According to the EFF (Electronic Frontier Foundation), these microdots have been used for at least a few decades to identify several things: the date and time of printing, and the serial number of the printer used.

None of This Is New

Of course, the whole idea of secret codes is nothing new at all. Steganography is a method of hiding secret messages in plain sight and it has a long history. Codes can be hidden in images and are even on many banknotes. In fact, many scanners and copiers contain instructions that tell them not to copy the so-called Eurion Star that appears on many banknotes.

Still, the fact that our very own printers sitting right in our homes print these tracking microdots is some cause for alarm. But is there any practical use for them? Can they be a tool for government surveillance?

Why Do Printers Add in Secret Tracking Dots?

It’s a sure thing that most people don’t have any idea that many printers add these microdots to each and every page as an identifying mark. Whatever one might think of them, there are a number of reasons why they might be useful:

Countering Forgery

Forging documents such as banknotes has only become easier with the advent of sophisticated new printing technologies. To keep up with these technologies, security measures have become more sophisticated too.

Whether it is the forging of official identity documents or leaked government documents, the presence of microdots makes it much easier to identify when and where they were printed, right down to the type of printer used. One might, for example, be able to provide evidence as to when a document was printed in a case and thereby allow it as evidence in court.

Tracking Criminal Behavior

The most obvious case for microdots is that they make it easier to track criminals and identify criminal behavior. The presence of microdots on a banknote indicates immediately that it is a counterfeit, for example.

The Blurring of Lines

On the surface, it might seem reasonable to add in microdots to track egregious criminal behavior and fight forgeries. The problem is that there is no legal reason why any agency should only restrict their surveillance to these activities.

Consider this: as your color laser printer secretly adds microdots to every page you print, are you willing to ignore the fact that this information can be used against you by unscrupulous individuals who are supposed to have our best interests at heart?

This is potentially where the lines between criminal behavior and whistle-blowing can be blurred, for example. Microdots do not just expose the criminals and master counterfeiters among us; they affect everyone. And how much difference is there between a criminal and a whistle-blower who might have just revealed more secrets about a government agency such as the NSA? As far as the government is concerned, the whistle-blower could very well be the bigger threat.

Printers That Don’t Add Microdots

If you want to avoid being tracked, the good news is that it only seems to be color laser printers that are affected. For now, your color ink-jet printer is safe. Having said that, laser printers are used widely in the business world and even in many home offices. Here’s a list of printers that the EFF says don’t add microdots. Check the model of the printer you own, you’ll want to identify your printer on the list.

Even though it seems that some companies don’t add the microdots, there’s a sting in the tail. It would seem that there is no guarantee that any recently produced laser printer does not add any sort of tracking information.

The EFF themselves admit that even the yellow microdots are not used by all printers. They may be adding tracking information in another form that is just as hard to decipher and read. In this context, it seems that this kind of tracking is here to stay for the moment.


Backed by overzealous governments with a distinct strain of authoritarianism running through their ranks, it seems that even the devices we use every day can be used against us. Even though there are clear uses in the fight against crime, we should all remain vigilant when it comes to our own freedoms and human rights, even when it comes to everyday devices like home printers.