Illinois state agencies, county prosecutors, insurance companies, and health care employers and associations are mandatory reporters --- they're required to report potentially dangerous and unprofessional doctors to medical regulators, who can bar the doctors from practicing and keep patients out of harm's way. But the mandatory reporters sound few alarms, and when they do, regulators rarely take action, the Tribune found. There were 348 mandatory reports filed with the state in 2009. That's out of nearly 46,000 physicians statewide. In only one case did the Illinois Department of Financial and Professional Regulation respond by suspending the physician's license, records show.