In 2007, Vermont passed a controversial new law known as section 17, banning the sale of prescriber-identifiable data (PI data) for marketing or promoting prescription drugs.

Pharmacies in Vermont and other states collect PI data when filling prescriptions. The information includes the prescriber's name and address; the name, dosage and quantity of the drug; the date and place the prescription is filled; and the patient's age and gender. Pharmacies sell PI data to data-mining companies, which aggregate it and strip it of patient information. The data miners sell the data mostly to pharmaceutical manufacturers, which use the trends revealed in the data to tailor their marketing to doctors.

By passing the law, state officials said they intended to protect public health and patient privacy and reduce health care costs. But several data-mining companies sued Vermont's attorney general, governor and secretary of human services, arguing section 17 unfairly restricts commercial speech. They said the law was unfair because PI data is widely used outside of marketing, and the law did not solve any of the problems it purportedly addressed.