Microsoft admittedly employs ETag cookies to track the online behavior of visitors on its homepage; activities especially beneficial to its ads serving campaigns.
A group of researchers had earlier made available a white paper on their findings in relation to the above lines: whereby, many popular websites were circumventing users privacy settings by deliberately restoring previously deleted HTTP cookies using local storage outside the control of the browser.
The findings in part, iterated the porousness of most browser privacy settings, allowing persistent tracking of users, even when such users had taken steps to avoid web profiling.
The tracking vectors assessed in the report included the following: Flash cookies, HTML 5 local storage and Cache Cookies via ETags.
ETags, according to the report, represent tokens by a users browser to a remote web server in order to determine whether a given resource had changed since its last profiling. The Cache cookie method used ETags, and is still capable of unique tracking, even when all cookies are blocked by user and 'Private Browsing Mode' is enabled.
The safe web initiative must above-all call to respect the 'do not track' status of users, and necessary legislation put in place to check its default.
