Loose restrictions in state law and scant oversight by regulators have allowed people to hijack Oregon's medical marijuana program for purposes voters never intended, The Oregonian's investigation revealed. Most patients are using the drug to treat chronic pain rather than terminal illness, far more marijuana is grown than patients consume, and traffickers ship the excess out of state for profit. At the heart of the yearlong investigation was a wide range of public records. First there were written documents: court records and police reports on medical marijuana growers; disciplinary actions against doctors who admit patients to the state program; internal policy manuals; and correspondence between regulators and doctors. Then there were electronic data. Through months of negotiations, the paper persuaded state health authorities to release a database of participants in the marijuana program that protected patient confidentiality. A separate database on Oregon State Police traffic stops helped us to demonstrate the widespread diversion of medical marijuana to the black market. Among the investigation's original results, published as an occasional series: Communities in southern Oregon have concentrations of marijuana patients 10 times the statewide average; Police patrolling Oregon's highways now seize more West Coast medical marijuana than pot grown outside the program; The state places few limitations on felons participating in the program, and dozens of trafficking prosecutions involve medical marijuana cardholders with existing criminal histories; Fifty-two children are legally permitted to use pot under the state program, with limited input from pediatricians or specialists treating their underlying illnesses; Nine doctors signed off on more than half the patients in the program, and 75 percent of patients used doctors with improbably high caseloads.