The post explains and recounts how two users managed to decrypt the embedded data to reveal the watermark. What's really surprising is that this tracking technique appears to have been in use by Blizzard since 2007!
Apparently more recent changes in the architecture of the game have, it is assumed, minimized any risk, but as the forum post notes: "Bear in mind that when this started, back in 2007, we were still using our account name to login so, before the battle.net conversion in 2009, the watermarks actually had really sensitive information ... Between May 22, 2007 and November 11, 2009, any malicious hacker who knew about this could have used a screenshot of a lucrative character to find their actual username & active realm and then either try to scam them out of their password, or just brute-force it."
There appears to be some disagreement over whether this watermarking invalidates the game's terms of service or not, but one thing that WoW users will not like is that they are still trackable outside of the game play without their knowledge or consent.
The need for more extensive and comprehensive digital privacy laws is becoming increasingly clear, and now that we know even game companies are abusing our privacy, where it will stop? How long until there's no privacy left anywhere online?
Read more about wide area network in Network World's Wide Area Network section.