Quoting Ken White at Popehat:
The blog Retraction Watch tracks, and probes, retractions in scientific journals. They say they do so because retractions are a “window into the scientific process,” because doing so helps create a repository of retractions and publicize them, because retractions can be the lead-in for a great story about misconduct, and because tracking retractions can help keep scientific journals honest.
Unsurprisingly, this does not make them popular among some of the scientists they cover. Last month a researcher at a well-known Texas cancer center menaced the site with a lawsuit, soon unleashing the Streisand Effect. And now, in a separate case, a pharmaceutical chemist is threatening to sue them because they reported on one journal’s “Expression of Concern” about one of his pieces, and in the terminology of scientific journals, an “Expression of Concern” is a different thing than a “Retraction,” which, he says, means that the website’s title is exposing him to defamation. Per Ken, this is not exactly the world’s most meritorious theory either.