Some colleagues/students think that it is fair, but unreasonable (waste of time, etc).
Dorothy Bishop makes a strong case that it is both reasonable and fair; excerpt:
Finally, a comment on whether it is fair to comment on a research article in a blog, rather than going through the usual procedure of submitting an article to a journal and having it peer-reviewed prior to publication. The authors’ reactions to my blogpost are reminiscent of Felicia Wolfe-Simon’s response to blog-based criticisms of a papershe published in Science: “The items you are presenting do not represent the proper way to engage in a scientific discourse”.
Read all of it, here.
On Twitter, Sophie Scott comments:
— Sophie Scott (@sophiescott) March 21, 2013
Indeed. Six papers in Nature journals, one in Science, PNAS, JACS, etc, and nanoparticles can still loose their stripes!