We seem to be systematically ill-treating our prisoners in a way that doesn't make any legitimate sense. If it's punishment, it's simply wrong because they haven't been tried. If it's for interrogation, it seems insanely excessive. If the argument is that "We are certain enough that Padilla had vital information that we are justified in confining him for years and treating him in any manner, no matter how psychically damaging not likely to cause organ failure in the hopes of extracting that information," I really want that argument to be made explicitly. What do they hope to find out from these people? And if we're claiming that the ill-treatment is necessary for security, that is patent nonsense. What was done to Padilla (and is being done to prisoners at Guantanamo) is obviously not necessary to keep them from escaping or hurting other people, and anyone putting forth that justification for blindfolding Padilla on his way to the dentist is either deceiving themselves or a liar.
This is all correct -- and there's an additional issue. Let's assume, for the sake of argument, that Padilla was an extremely dangerous man who should have been locked up (although the government can't actually substantiate the most serious charges against him.) As Andrew Sullivan points out, torturing Padilla is also counterproductive because it will make it extremely difficult to convict him. This kind of systematic mistreatment of prisoners is an utter disgrace on every level: moral, political, legal, and pragmatic.