Researchers from Princeton University (PU) and KU Leuven University (KULU) released a study (The Web Never Forgets - Persistent Tracking Mechanisms in the Wild) on canvas fingerprinting (CF) provided by AddThis which is the ability to instruct a web browser,
CF tells web browsers "to draw a hidden image, and each computer produces a slightly different, unique image" that will follow each individual user online as they travel from website to website.
This technique was invented by AddThis two years ago.
Shockingly, 5% of the biggest websites on the internet already use CF, including:
Casey Oppenheim, co-founder of Disconnect said:
Rich Harris, chief executive officer for AddThis commented:
CF is present on an estimated 5,542 of the top 100,000 on the internet thanks to AddThis and 20 other corporations who offer a similar product to CF.
User tracking is common among web browsers that use advertising such as Google’s Double Click which allows website owners to earn money from tracking visitors.
Gunes Acar, lead researcher and student with the department of Computer Security and Industrial Cyrptography at KULU, stated:
It is claimed that most AddThis clients are unaware of the tracking technology.
Another feature to this monitoring software is that when the opt-out is chosen, the tracking is still happening while AddThis maintains that the information collected is "not being used".