According to Princeton University, this technique has been already in use at more than 5,000 sites under test. It is just 5% of the total 1 lakh sites being tested and the rest 95% scripts come from just one provider i.e. (addthis.com). It was found that twenty canvas fingerprint provider domains were quite active on 5542 out of 100,000 sites.
The researchers at Princeton said that they have found the existence of subtle loopholes in the assessment of protection techniques employed by the privacy conscious users. AddThis is the single provider of the scripts that were employed by the sites using ‘canvas fingerprinting’. It is the one that is using the advanced version of the technique. Later it was found that PlentyOfFish, a dating site was also using the technique.
The test actually tries to use the default font (fallback) of the browser by asking for a non-existent font. The test helps in differentiating the various OS and browsers. AddThis Solutions has reached an overwhelming 97.2% of the total US internet users and as received 103 billion page views in a month.