Before pharmaceutical company marketers call on a doctor, they do their homework. These salespeople typically pore over electronic profiles bought from data brokers, dossiers that detail the brands and amounts of drugs a particular doctor has prescribed. It is a marketing practice that some health care professionals have come to hate. Marketing to doctors using prescription records bearing their names is an increasingly contentious practice, with three states, Maine, New Hampshire and Vermont, in the vanguard of enacting laws to limit the uses of a doctor's prescription records for marketing. Today, the Supreme Court will hear arguments in a case, Sorrell v. IMS Health, that tests whether Vermont's prescription confidentiality law violates the free speech protections of the First Amendment.