m00t wrote on Sep 11, 2012, 19:22: It was probably used to identify people breaking NDA for WOTLK. According to TFA it first showed up in early WOTLK alpha builds.
That would be my guess as well. It's a rather smart move on Blizzard's part; this must have made it very easy to ID hackers, leakers, etc. I just hope this isn't the only such tool in Blizzard's chest, as otherwise it's going to suck if they've lost their primary way of IDing violators.