(CNN) -- The U.S. should stop arresting responsible marijuana users, Rep. Barney Frank said Wednesday, announcing a proposal to end federal penalties for Americans carrying fewer than 100 grams, almost a quarter-pound, of the substance.
Current laws targeting marijuana users place undue burdens on law enforcement resources, punish ill Americans whose doctors have prescribed the substance and unfairly affect African-Americans, said Frank, flanked by legislators and representatives from advocacy groups.
"The vast amount of human activity ought to be none of the government's business," Frank said on Capitol Hill. "I don't think it is the government's business to tell you how to spend your leisure time."
The Massachusetts Democrat and his supporters emphasized that only the use -- and not the abuse -- of marijuana would be decriminalized if the resolution resulted in legislation. Watch Frank lay out the proposal »
The Drug Enforcement Administration says people charged with simple possession are rarely incarcerated. The agency and the White House Office of National Drug Control Policy have long opposed marijuana legalization, for medical purposes or otherwise.
Marijuana is a Schedule I controlled substance, meaning it has a high potential for abuse and no accepted medical use, according to the drug control office.
"Smoked marijuana has not withstood the rigors of science -- it is not medicine and it is not safe," the DEA states on its Web site. "Legalization of marijuana, no matter how it begins, will come at the expense of our children and public safety. It will create dependency and treatment issues, and open the door to use of other drugs, impaired health, delinquent behavior, and drugged drivers."
Allen St. Pierre, spokesman for the National Organization for the Reform of Marijuana Laws, likened Frank's proposal -- co-sponsored by Rep. Ron Paul, R-Texas -- to current laws dealing with alcohol consumption. Alcohol use is permitted, and the government focuses its law enforcement efforts on those who abuse alcohol or drive under its influence, he said.
"We do not arrest and jail responsible alcohol drinkers," he said.
St. Pierre said there are tens of millions of marijuana smokers in the United States, including himself, and hundreds of thousands are arrested each year for medical or personal use. iReport.com: Is it time to legalize pot?
There have been 20 million marijuana-related arrests since 1965, he said, and 11 million since 1990, and "every 38 seconds, a marijuana smoker is arrested."
Rob Kampia, director of the Marijuana Policy Project, said marijuana arrests outnumber arrests for "all violent crimes combined," meaning police are spending inordinate amounts of time chasing nonviolent criminals.
"Ending arrests is the key to marijuana policy reform," he said.
Reps. William Lacy Clay, D-Missouri, and Barbara Lee, D-California, said that in addition to targeting nonviolent offenders, U.S. marijuana laws unfairly target African-Americans.
Clay said he did not condone drug use but opposes using tax dollars to pursue what he feels is an arcane holdover from "a phony war on drugs that is filling up our prisons, especially with people of color.CNN News