Sabine Hossenfelder at Back Reaction has a great post -- Open Peer Review and Its Discontents -- about the role of commentary (in blogs, FB and G+ streams, etc) on papers that have already appeared in the public domain either as a journal article or as pre-prints at sites arXiv.org. Her post is triggered by a "back reaction" of sorts from an author whose paper came in for some open criticism in her blog; this is what she says about this reaction:
Hummel [the journalist who wrote about the article in a German magazine] wrote by email he found my blogpost very useful and that he had also contacted the author asking for a comment on my criticism. The author’s reply can be found in Hummel’s article. It says that he hadn’t read my blogpost, wouldn’t read it, and wouldn’t comment on it either because he doesn’t consider this proper ‘scientific means’ to argue with colleagues. The proper way for me to talk to him, he let the journalist know, is to either contact him or publish a reply on the arxiv. Hummel then asked me what I think about this.
To begin with I find this depressing. Here’s a young researcher who explicitly refuses to address criticism on his work, and moreover thinks this is proper scientific behavior. I could understand that he doesn’t want to talk to me, evil aggressive blogger that I am, but that he refuses to explain his research to a third party isn’t only bad science communication, it’s actively damaging the image of science.