I wasn't following it closely (and was a little disgusted) but as I recall, all lukedashjr did was mine for a while then quite and it had a devastating impact on whatever coin it was.  Hell, the same thing could happen to Bitcoin without any attack if the price drops steeply or suddenly (but that could never happen, right?) and/or a few large clusters were molested.  I'll call this an 'Invisible hand of Adam Smith lukedashjr Attack.'  Maybe the adjustment algorithms have been patched up to preclude this, but I doubt it...such things occurring proactively seem rare in Bitcoinland.