There are currently two legal proceedings pending which may have the effect of focusing official -- as opposed to academic and media -- attention on the legal advice given by OLC lawyers on the permissibility of certain "enhanced interrogation techniques." One is the lawsuit by Jose Padilla against John Yoo (and many others, including former SecDef Donald Rumsfeld) alleging that he had been subjected to cruel, inhuman, and degrading treatment amounting to a deprivation of his constitutional advice. There have been extensive discussions of this lawsuit in various blogs, including a post by our very own John Steele, as well as David Luban's post over at Balkinization. The second proceeding is the recently reported internal investigation by the Justice Department's Office of Professional Responsibility. That investigation is aimed at determining whether OLC lawyers violated their ethical obligations by concluding that waterboarding, among other "enhanced interrogation techniques," is lawful. Marty Lederman and David Luban disagree over whether there is any point to this investigation. Since Lederman and Luban are just about the most knowledgable people around, with respect to these issues, I've been wondering what they disagree about.