It has been reported that over 150 of the world’s most popular websites use a hidden method called Fingerprinting. Fingerprinting creates a digital fingerprint of your device by gathering information such as the resolution of the screen, operating system, the fonts that have been installed, and many more characteristics. This enables individual devices to be recognisable and thus trackable – regardless of their standard privacy settings.

These sites can then use this information in a variety of ways, for example, to know if you have visited before and to create advertising around your usage. Mainly the risk is to anonymity, which fingerprinting completely destroys. It is even possible for sites to use Fingerprinting if you are in “private browsing” mode (where cookies are disabled) or when using a virtual private network (where your IP address is hidden). Fingerprinting can even distinguish users that have set “do not track” in a browser and use this as a recognisable feature.

Large renowned websites such as CNN.com, BestBuy.com, Nytimes.com and Costco.com all use Fingerprinting. It has been shown the most common reason is for marketing, however, how exactly the data is used is unclear. The New York Times stated: “We don’t use fingerprinting to track our readers and have internal rules forbidding it,”. Other websites implicated in this discovery, for example US federal agencies such as the Internal Revenue Service and State Department, responded that they will remove this code from their sites.

Google, Apple and Mozilla have identified Fingerprinting as a growing threat. Google’s Chrome browser engineers commented, “Because fingerprinting is neither transparent nor under the user’s control, it results in tracking that doesn’t respect user choice”. The Chief Technology Officer of privacy software company Disconnect also confirms the concern of Fingerprinting: “Your browsing history, the apps you use and the data you give companies can lead to voter manipulation, targeted behaviour modification, and further aids the mass surveillance of our activities on and offline.”

Being conscious of the browser you use can be beneficial. Apple’s Safari is likely the most protected as it actively reduces the amount of information it shares, such as only revealing a list of built-in fonts (instead of custom ones). For non-Apple devices, Firefox is a good consideration. Firefox has aggressive default protection from cookies and is nearing completion in adding default Fingerprinting protections. An early version of these protections can be turned on now by going to the “Custom” tab under privacy and security settings.

Google’s Chrome browser is one of the most used browsers. Currently Chrome doesn’t do much to stop fingerprinting by default, however, privacy extensions such as Canvas Blocker or Jackson’s Disconnect can be added to help stop some fingerprinting. Despite the lack of protection, Google has promised it will reduce the ways in which browsers can be passively fingerprinted.