The price of “free” internet services continues to surface. Following Facebook’s emotional engineering, AddThis (a company provides social sharing buttons for websites) is also, it seems, in the business of experimenting on the backs of the people it serves without them knowing about it:
” … Like other tracking tools, canvas fingerprints are used to build profiles of users based on the websites they visit — profiles that shape which ads, news articles, or other types of content are displayed to them.
But fingerprints are unusually hard to block: They can’t be prevented by using standard Web browser privacy settings or using anti-tracking tools such as AdBlock Plus.
… The researchers found canvas fingerprinting computer code, primarily written by a company called AddThis, on 5 percent of the top 100,000 websites. Most of the code was on websites that use AddThis’ social media sharing tools.
… Rich Harris, chief executive of AddThis, said that the company began testing canvas fingerprinting earlier this year as a possible way to replace “cookies,” the traditional way that users are tracked, via text files installed on their computers.
“We’re looking for a cookie alternative,” Harris said in an interview.
Harris said the company considered the privacy implications of canvas fingerprinting before launching the test, but decided “this is well within the rules and regulations and laws and policies that we have.”
… AddThis did not notify the websites on which the code was placed because “we conduct R&D projects in live environments to get the best results from testing,” according to a spokeswoman.”
I know about AddThis because I create websites and care about privacty (and therefor don’t use AddThis). However if you are an end-user who “only” browses websites and think to yourself “I don’t use AddThis”, think again. Any website that you visit that uses AddThis is enabling AddThis to use you.