Baird (D) was convicted in a bench trial for exhibiting contraceptive articles during a lecture he was giving at Boston University, and for giving a young woman a package of Emko vaginal foam at the close of his address. The statutory scheme distinguishes among three distinct classes of distributees -- first, married persons may obtain contraceptives to prevent pregnancy, but only from doctors or druggists on prescription; second, single persons may not obtain contraceptives from anyone to prevent pregnancy; and, third, married, or single persons may obtain contraceptives from anyone to prevent not pregnancy, but the spread of disease. It was a felony for anyone, other than a registered physician or pharmacist acting in accordance with the terms of § 21A, to dispense any article with the intention that it be used for the prevention of conception. The Supreme Judicial Court set aside the conviction for the exhibiting the articles but sustained the conviction for giving away the foam. Massachusetts law required that such products could only be given by a physician or a registered pharmacist to married persons. D subsequently filed a petition for a federal writ of habeas corpus, which the District Court dismissed. On appeal, the Court of Appeals vacated the dismissal and remanded the action with directions to grant the writ discharging D. This appeal by the Sheriff of Suffolk County followed. The Supreme Court granted certiorari.