Beleaguered social media giant Facebook has removed "treason" from their database of the keywords assigned to users for advertising purposes, the company stated Wednesday after Danish state broadcaster DR reported its existence.

Company spokesman Joe Osborne replied "National treason was an advertising interest because of its historical significance, but as it is an illegal act, we have removed it."

Facebook tags its more than 2 billion users with a wide variety of keywords depending on their interests - from shopping habits to political and religious views in order to sell more efficiently targeted advertising.

This makes Facebook a sublime sales channel for companies. Categorizing users in areas of interest means that companies with ads on Facebook can buy into an almost perfect audience. Eg. garden equipment for people with special interest in gardens, etc. But categorization also allows intelligence services in all countries to look at the population over the shoulder.

DR suggests that the a government such as Russia could have used the "treason" tag to locate around 65,000 Facebook users who had been marked with the keyword. The article notes that they do not know "if the Russian authorities have used Facebook's "treason" keyword" for nefarious purposes - adding "Only the Russian authorities know that."

Social media expert Halfdan Timm outlined how easy it would be for bad actors - including oppressive governments - to target people by sending targeted advertising designed to get those users to click on a website URL - which would record the IP address of each visitor.

First, you could go into Facebook's advertising system. Here you could choose to target everyone living in Russia, and everyone who had the advertisement 'land treason'. In the advertisement there should be a link to a website that you own. This ensured that the only ones who clicked on the link were those who had been stamped as interested 'treason' and lived in Russia. The advertisement did not have to do anything with treason. It could also be of the more entertaining kind of "see which war hero you look like most" or a great deal on some new shoes. "Making people click on a link is the most commonly used ad target," explains Halfdan Timm.

"There are almost no limits to what you can do," emphasized Søren Debois, and IT expert at IT University - who added:

"All persons entering any website leave their IP address to the website owner. As a intelligence service, it can be used to find out where you live. If they use phishing, they can find your name, your bank, your phone number, your email."

Facebook says they take action when this type of activity is detected.