Metro subway stations and buses -- law-and-order places where eating a french fry has gotten people arrested -- began displaying advertisements this week that suggest marijuana use should be decriminalized.

The ad campaign, rejected by Boston's subway system and the subject of a pending lawsuit there, was funded by Change the Climate Inc., a nonprofit organization that believes punishment for marijuana use is too harsh.

"We are business owners and parents who are increasingly concerned that the punishment far outweighs the crime," said Joseph White, 45, a partner in a Massachusetts-based telemarketing and opinion research firm who formed the group last year. "We want the politicians and thousands of people who are going to be here for inauguration month to take an interest in the issue."

Change the Climate Inc. approached both Metro and the Massachusetts Bay Transportation Authority in Boston early last year, seeking approval for its advertising. "We like transit agencies because we want to reach average Americans," White said.

Metro officials initially refused the ads, citing a policy that says public service advertising must be noncommercial, nonpartisan and "not designed to influence legislation or public opinion on a controversial subject," spokesman Ray Feldmann said.

But when threatened with a lawsuit backed by the American Civil Liberties Union arguing that Metro was violating free speech, officials relented. Metro is also reviewing its policy, Feldmann said.

The legal challenge would have been similar to one faced by the MBTA in Boston. Massachusetts Gov. Paul Cellucci (R) has refused to settle that case, arguing that the ads promote marijuana use.

Change the Climate Inc. paid Metro a discounted advertising rate for nonprofits of $2,150 in exchange for illuminated signs on 10 subway platforms, large exterior signs for 50 buses and smaller signs for the interiors of an additional 500 buses, Feldmann said.

The month-long campaign consists of three ads. The first, which is in the stations -- including the one closest to the White House -- features a young woman who asks, "Why do kids go to jail for doing what politicians did when they were young? Tell us the truth."

Justin Cohen, a 25-year-old lawyer from Chevy Chase, was drawn to that ad while waiting for a train at the McPherson Square station yesterday. "It's a good ad," he said. "I was even going to check out the Web site. I'm already leaning towards that point of view. We need to change the way we handle marijuana. . . . Good kids just experiment, but if they get caught, it can ruin their lives."

The second ad, inside buses, shows a business executive with cancer who admits to smoking marijuana after chemotherapy. The third, which appears outside the buses, features two police officers in front of an American flag. It reads, "Police are too important . . . too valuable . . . too good . . . to waste on arresting people for marijuana when real criminals are on the loose."

All ads carry a disclaimer that Metro does not endorse the message.

White said his group is not trying to legalize marijuana but rather reduce the penalties so it is not in the same category as heroin and other "hard" drugs. "Over 4 million people have been arrested since 1992, and most of those arrested have been young people -- our own children," said White, a father of three, who lives in Greenfield, Mass. "Most responsible parents don't want their kids smoking marijuana, but we don't want our children arrested, jailed and terrorized in the manufactured hysteria surrounding marijuana."

But Howard Simon, of Partnership for a Drug Free America, called the advertising campaign "disingenuous."

"Most people see this for what it is: an attempt by a vocal minority to make marijuana more socially acceptable," Simon said. "One of the ads says, 'Tell us the truth.' Well, the truth is the vast majority of Americans want marijuana to remain illegal. The truth is that medical marijuana should be decided by the medical community. That's the truth. We don't think these ads are going to be very effective."

Change the Climate Inc. plans to expand its transit ads to New York and Chicago. "We think that having an ad campaign in the nation's capital will make it easier for us in other cities," White said.An ad funded by Change the Climate Inc. at McPherson Square says that punishment for marijuana use is too harsh.