"Physicians are concerned that their prescribing decisions and patterns may be questioned and that they could be investigated without sufficient cause. Some physicians contend that patients may suffer because physicians will be reluctant to prescribe appropriate controlled substances to manage a patient's pain or treat their condition. Patients are concerned that their personal information may be used inappropriately by those with authorized access or shared with unauthorized entities. Pharmacists have also expressed concerns."

Source

General Accounting Office, "Prescription Drugs: State Monitoring Programs Provide Useful Tool to Reduce Diversion" (Washington, DC: Government Printing Office, May 2002), GAO-PO-634, p. 18.
http://www.gao.gov/new.items/…