A bill being proposed in the Washington state Senate would prevent prescription drug companies from "data mining" physicians' records--a process by which pharmaceutical companies buy prescription information from pharmacies to cross-check against a list of doctors' prescription ID numbers. The bill initially had widespread Senate support, but it passed by a narrow margin after concerns about limits it would place on the spread of AIDS-prevention drug information. Some say legislators thought the bill was overly aggressive because doctors already have the option of opting out of data collection.