More than 16,000 people have signed a petition demanding that the head of the Drug Enforcement Administration (DEA) be fired for calling medical marijuana a "joke" last week.

"What really bothers me is the notion that marijuana is also medicinal — because it's not," DEA Administrator Chuck Rosenberg said during a press briefing on November 4. "We can have an intellectually honest debate about whether we should legalize something that is bad and dangerous, but don't call it medicine — that is a joke."

Rosenberg hastened to add that "extracts or constituents or component parts" may hold promise as medicinal substances, but that smoking "the leaf" of the marijuana plant has never been shown to be safe or effective. (The DEA chief apparently confused marijuana leaves, which contain only trace amounts of the psychoactive compound THC, with buds, which are far more potent and commonly smoked.)

Medical marijuana advocates quickly criticized Rosenberg, complaining that the DEA blocks medical and scientific research on weed. Many of the petition's signatories include patients with chronic illnesses who say pot has changed their lives.

'It worries me that he is so ignorant as to say that it's a joke. My daughter's medicine is not a joke to me.'

"While it's nothing new for drug war bureaucrats to oppose sensible marijuana policies, Rosenberg's comments go way too far," the petition, posted on Change.org, reads. "Medical marijuana is not a "joke" to the millions of seriously ill patients in a growing number of states who use it legally in accordance with doctors' recommendations."

The petition calls for President Barack Obama to "fire Chuck Rosenberg and appoint a new DEA administrator who will respect science, medicine, patients and voters."

The petition was started by Tom Angell, a leader of the pro-pot advocacy group Marijuana Majority. Angell told VICE News he hopes the number of signatures — including one by singer Melissa Etheridge — will "get the White House to take note that this administration's DEA head is saying things that are offensive to millions of American families who have benefited from medical marijuana."

Obama: Fire DEA Head for Calling Medical Marijuana a 'Joke' - Sign the Petition! — Melissa Etheridge (@metheridge)November 6, 2015

The head of the DEA should show an openness toward scientific inquiry and medical opinions on the effectiveness of pot in accordance with the President's position, Angell said.

"The DEA has historically been ardently opposed to any sort of marijuana reform, but the president has said let's let science, not ideology, dictate our policies. If he really believes that then before he leaves office he should appoint someone as head of the DEA who is willing to abide by science and what science says on drugs," Angell said.

Elizabeth Collins, the mother of a 16-year-old girl with chronic epilepsy, is a vocal advocate for legislation that allows medical marijuana. Collins said she has tried to meet with Rosenberg and other DEA officials to try and explain how helpful a marijuana extract has been for her daughter, but she's never gotten a response. Collins signed the Change.org petition.

"I think someone who has that amount of power over arrests having to do with a substance should be well-versed on the substance and be able to speak factually about it," Collins said. "It worries me that he is so ignorant as to say that it's a joke. My daughter's medicine is not a joke to me."

Her daughter, Jennifer, suffered between 300 and 500 seizures a day and was once heavily medicated on pharmaceuticals, which caused side effects that ranged from depression and self-harm to rage and harming her mother. Jennifer lost her ability to focus and think clearly in school as well, Collins said.

Two years ago, Elizabeth and Jennifer left the rest of their family behind and traveled from their home in Virginia, where medical marijuana was illegal, to Colorado, which has legalized the drug for both medical and recreational use. They ultimately returned to Virginia, and Elizabeth successfully lobbied the state legislature to allow her to administer the marijuana extract to her daughter.

Watch the VICE News documentary** Inside America's Billion-Dollar Weed Business: The Grass Is Greener:**

"After starting the treatment she was able to go down on medication to only one pill and all those behaviors have stopped. She's doing much better in school, she's able to think," Collins said. "[Jennifer] says it's completely changed her life."

Collins has met with the Food and Drug Administration (FDA) and the Office of National Drug Control Policy to make her case for a change to federal laws. She says the petition shows the anger that citizens feel toward the DEA and legislators who refuse to loosen restrictions on medical marijuana research.

"They're not listening to the people. The majority of American people want access to this medicine and lawmakers aren't doing what we want and that's really, really frustrating," she said.

The DEA did not respond to a request for comment from VICE News.

Angell said his own mother uses marijuana to treat severe pain in her legs caused by multiple sclerosis. He disagreed with the Rosenberg's claim that extracts are the only legitimate form of medical marijuana.

"Right now patients are suffering and doctors recommend they use whole plant marijuana and they are legally able to do that under state law. We shouldn't criminalize that while we wait for the pharmaceutical industry and regulators to develop these other medications."

He also pointed out that science aside, Rosenberg is politically out of touch with the way most of America feels about medical marijuana. The activist cited polls that found an overwhelming percentage of Americans think medical marijuana should be legal. Twenty-three states and Washington, DC have already changed their laws to allow some form of medical marijuana.