Finishing up his three-part series for FindLaw, in which he calls the Rhode Island court's dismissal of the lead paint case "the right answer for the right reasons", the Cardozo lawprof singles out perhaps the most important point that distinguishes legitimate old from spurious new applications of public nuisance law: "the Court held that the law of public nuisance requires not only that the defendant be a substantial cause of the interference, but that the defendant still be in control of the instrumentality that caused the interference at the time when the suit is brought." (via Scheuerman, TortsProf).