Hi,
Dkopener,
Unfortunately, these people have had their machine 'fingerprinted' by Bliz. It will take some Google research to correct this problem.
Wikipedia has a very generic explanation of fingerprinting. There are
no known legitimate uses of fingerprinting a machine you do not own—fingerprinting a machine you do not own is limited to nefarious purposes, only. Unfortunately, the laws in most countries turn a blind eye to this problem because it is almost impossibe to prove.
To demonstrate the concept at a higher level, your browser can be
uniquely identified even with cookies disabled. (This is not how Bliz is doing it, but it clearly demonstrates the principles involved.) To see for yourself, head on over to
Panopticlick, run the test, and pay attention to the "Does your browser protect from fingerprinting?" result. Repeat the test with your browser's "Incognito mode", and you'll not see much progress.
To see how difficult the problem is to correct, try making adjustments such that your browser is not uniquely identifiable. Once you've mastered that, you may start to see the difficulty of solving the problem for
your machine, which has a
lot more uniquely identifiable information available than just your browser. Many believe a VM or changing IPs can adjust the machine's fingerpint. Unfortunately, this is not near enough. A VM has about the same effect as a browser's "Incognito mode"—it changes things
a little, but not near enough to be effective.
cheers,
chinajade