This story on Slashdot Games reveals that screenshots taken in World of Warcraft have secret watermarks that can be used by Blizzard to track users - particularly when they are engaged in behavior considered to be illegal or that violates World of Warcraft's terms of service.
The story began a few days ago when a World of Warcraft players noticed that there was an odd mark on a screenshot he had taken in-game:
New submitter kgkoutzis wrote: "A few days ago I noticed some weird artifacts covering the screenshots I captured using the WoW game client application. I sharpened the images and found a repeating pattern secretly embedded inside."
He goes on to say that he posted the image on Owned Core, where multiple people within that community researched and experimented with WOW screenshots. So what did they find?
That the watermark inside every screenshot taken within WOW includes "user IDs, the time the screenshot was captured and the IP address of the server" the screenshot source was on.
The author of the Slashdot post points out that Blizzard did not notify users in its terms of services that it had or would use the ability to track them through screenshots they take and post to the community.
While it is certainly a clever way to track bad actors who engage in everything from gold farming to hacking, it is also a fact that no one at the company ever disclosed.
You can read about how Owned Core users figured out that Blizzard had hidden these codes in screenshots here.
Source: Slashdot Games