Today hundreds of people suffering from AIDS, cancer, multiple sclerosis and other terrible illnesses, along with their families, friends and supporters, peacefully protested at dozens of Drug Enforcement Administration offices around the country. They came with one simple request: Stop trying to take away our medicine.

As District Attorney of San Francisco, I support their effort, and I implore the DEA to stop its attack on the medical use of marijuana.

In 1996, 56 percent of California voters -- some five million people -- endorsed legalizing medical marijuana by voting yes on Proposition 215. In my city the yes vote was 80 percent. The measure even carried Orange County, one of the most conservative areas of the state. Since then, seven other states have adopted similar laws, six of them by votes of the people.

George W. Bush recognized that public sentiment during his 2000 presidential campaign. He told the Dallas Morning News that, while he was personally opposed to medical marijuana, he believed states should be able to decide the issue "as they so choose."

As president, however, Mr. Bush has taken a different course. Justice Department lawyers -- continuing a Clinton administration policy -- have argued in federal court that the government has the right to take away the prescribing rights of doctors who recommend marijuana to patients. In other words, the administration believes that politicians and bureaucrats should be able to dictate to your doctor what advice he or she can give you.

Armed DEA agents have raided medical marijuana dispensaries operating legally under state law in San Francisco, Los Angeles and El Dorado counties, seizing patient records and sending waves of fear up and down California. Some of these facilities have been forced to close permanently.

These raids do not help local law enforcement or protect the public health or safety. Instead, they endanger our most vulnerable citizens and make my job as District Attorney more difficult.

From a law enforcement perspective, Proposition 215 has been implemented successfully in San Francisco. It has reduced crime as well as the costs associated with arrest, prosecution and incarceration. It contributes to public health and safety.

Our Department of Public Health has established a system of identification cards that protects patient confidentiality while helping law enforcement identify documented medical marijuana patients. Nonprofit medical marijuana dispensaries have become an important part of this system, providing a safe, quality-controlled supply of medicinal cannabis to seriously ill people and working closely with local law enforcement and public health officials. Many also function as support groups for people who often are very, very ill.

But it is precisely these dispensaries that the DEA has raided. Patients and their caregivers have been calling my office asking for reassurance that their access to a medicine they rely on will not be denied -- reassurance I would like to be able to give them, but cannot. At any moment the DEA could stage more raids, depriving sick people of their medicine or forcing them to turn to street drug dealers instead of safe, supportive providers.

I hope the DEA, the Justice Department and the entire Bush administration will heed the "Cease and Desist" orders delivered by yesterday's protesters. Surely at a time when we face so many real threats -- like the senders of anthrax-laced letters who still have not been caught -- the federal government has better things to do than to deprive sick people of their medicine.

Terence Hallinan is the district attorney of San Francisco