Hyves PageRank Penalty

Recently, a rumour was circulated by Marcus Tander – aka Mediaadonis (a marketing consultant) that if you apply a the word hyves as a sub-domain before your own domain name it would show you whether you had been given a penalty for selling links. If it showed as PR 7 in your PR-meter, it was okay.  If it was a PR 4, then your site had a penalty against it. It could also be PR 0 if you were banned.
At the time it seemed quite bizarre that this would work but many were posting about it.  It is good to ask questions before believing anything.

• How does it work?
• Why would this work?
• How was it discovered?

Given that none of these questions has an answer and very few people were ever able to make it work and document it. It would seem that this has nothing to do with Google at all but marketing hype for a hyves.nl – a social media site in the Netherlands. I wonder if it has anything to do with this?