Privacy is a topic that I closely followed since early 2000s. Before
we were addicted to free email accounts, the nascent ad-supported
free Internet services industry left a lot of questions unanswered with
respect to how they collect data and what they do with it.
After more than a decade, a Netscape invention called browser cookies is
at the forefront of privacy battle.
If you're like so many other concerned netizens, you're most likely using a
privacy enhancing browser plug-in such as
ABP, Ghostery,
uBlock. Well, I have a disturbing update:
your efforts to circumvent all this unsolicited tracking behavior on
the Internet are may be an exercise in futility. There are a new generation
of persistent tracking techniques employed by the ad companies to slice and
dice all unassuming web citizens of the world by some cunning methods.
One is called canvas fingerprinting, which in essence, is an abusive
use of a feature, Canvas API, in modern browsers that track subtle
differences in rendering of text or other patterns on the browser window.
While, by itself, it's not enough to uniquely identify a person based on
its machine's graphical processing capabilities, coupled with other
information such as installed plugins, screen resolutions, Javascript
capabilities, etc, it does not take much to find out who exactly is browsing
the site (Using less that 10 different feature vectors, it was shown to
be possible to uniquely identify someone).
Other techniques are even more sinister, because they
restore cookies deleted previously and share that information across
different sites by something called cookie syncing. Historically, when a
user clears his cookies and restarts browsing, the third parties will
construct a new history graph. Since these graphs belong to different
tracking IDs (or user ids), trackers cannot associate the individual's
history before and after cookies were cleared. However, if another
tracker respawns a particular cookie, parts of two history graph
may be linked by a node, thereby identifying both history graphs with
you.
There is a lot at stake for online advertising industry. Therefore, they
have the wherewithal to explore any and all avenues to make sure that
constant revenue stream continues to flow.