"Our Supreme Court just a year ago said it was okay for doctors to recommend and they can't be prosecuted for telling patients to use it. Therefore, doctors can tell you to use it," said medical marijuana user and talk show host Montel Williams on . "But once they tell you to use it, they can come and prosecute you. How ridiculous is that?"
The justices concluded that from a federal ban on the drug.
The decision is a defeat for medical marijuana advocates who had lobbied successfully in 10 states to allow marijuana use for medical reasons.
Justice John Paul Stevens, writing the 6-3 decision, said that Congress could change the law to allow medical use of marijuana.
The closely watched case was an appeal by the Bush administration in a case that it lost in late 2003. At issue was whether the prosecution of medical marijuana users under the federal Controlled Substances Act was constitutional.
The ruling is a serious setback not only for proponents of medical marijuana who say it is helpful for serious and chronic pain, but also for states' rights, reports CBS News Correspondent Bob Fuss.
"The sideshow of medical marijuana has led some teenagers to believe marijuana is not only not harmful for you, its good for you, it's medicine. That's not true," said federal drug enforcement chief John Walters.
Justice Sandra Day O'Connor wrote in the minority opinion that the federal law 'stifles an express choice by some states concerned for the lives and liberties of their people."
Crime fighters in California and other states with medical marijuana laws insisted they were not about to start looking for reasons to shut down the dispensaries.