This week lawyers for Virginia pain doctor William Hurwitz, who was sentenced last spring to 25 years in federal prison for drug trafficking, filed an appeal brief that explains why physicians (and patients) throughout the country should be concerned about the precedent set by this case. The most important argument for overturning his conviction is that the prosecutors did not prove he knowingly violated the Controlled Substances Act. Instead they showed that some of his patients faked or exaggerated their pain to get narcotics they sold on the black market. The prosecutors also presented testimony from a pain specialist who said Hurwitz's narcotic prescriptions for legitimate patients were excessive--testimony that was contradicted by other expert witnesses. The Justice Department argued that it did not matter whether Hurwitz prescribed narcotics in a good-faith effort to treat his patients' pain, because he was operating outside the bounds of legitimate medicine, whether he realized it or not. This argument, which was accepted by the judge, influenced the admission of evidence, and shaped the jury instructions, turns the DEA and the Justice Department into a national medical board that can second-guess doctors' prescription decisions and impose heavy criminal penalties for those it considers inappropriate. Whatever they may think of Hurwitz's practice, his colleagues should be worried.