He seems to be one of the leading advocates against Austrian economics. Has anyone challenged him and if so where can I find it? Sraffa is his inspiration. http://robertvienneau.blogspot.com/
what do you mean 'leading advocate'?, he is a self-described hobbyist and his blog lists 14 followers.
and he blogs about Nietzche?
Where there is no property there is no justice; a proposition as certain as any demonstration in Euclid
Fools! not to see that what they madly desire would be a calamity to them as no hands but their own could bring
There are other, more prominent opponents of Austrian economics. Vienneau is one of the only people who has made it the focus of his thoughts, however. Also, his critiques are quite specific, rather than a general anti-Austrian critique, so I don't really see a need to challenge him.
Vienneau is sometimes cited as a critique of Austrians. If I remember correctly, no one challenged him directly. His ... hm ... "critiques" of ABCT can be found here : Some Fallacies Of Austrian Economics - September 2006 (read section 5) Some Capital-Theoretic Fallacies in Garrison’s Exposition of Austrian Business Cycle Theory - September 2010 (read section 3)