Editor's note: Amanda Reiman is the California policy manager for the Drug Policy Alliance and a lecturer in the School of Social Welfare at the University of California, Berkeley.
(CNN) -- Today, April 20, is "420: International Marijuana Day." Festivals and marches are planned around the world. The number 420 reflects the date, but it also represents the term's clandestine origin in the 1970s, brought about by laws that still plague cannabis consumers today.
In 1971, a group of high school friends, the "Waldos," invented 420 as a code word for smoking pot. Referring to 4:20 p.m. after school, the friends from San Rafael, California, would meet to smoke marijuana in their secret spot next to a wall -- the origin of their nickname. In the 40 years since, 420 has spread to become an international symbol for using marijuana, and it's a part of the cannabis consumer's vocabulary.
Threatened with jail and unemployment, people who use marijuana in most states must hide their activities. In 2011, more than 750,000 people were arrested for marijuana possession and sales in the United States. In 2010, 86% of those charged for possession in New York City were black or Latino. That, even though these groups represent about half the city's population and use marijuana less than whites.
But, slowly, support for cannabis regulation is growing.
A recent Pew research poll found that 52% of Americans support taxing and regulating marijuana, a historic high. It isn't that more people are using marijuana -- those rates have remained stable -- it's that more people feel they can come out of the closet about their support for marijuana policy reform.
Websites like the Marijuana Majority feature statements from celebrities and politicians in favor of marijuana policy reform, across the political spectrum, from Bill Maher to Pat Robertson. No longer a part of a fringe, those who see a better way to regulate marijuana are casting aside the secret codes and openly declaring support.
The marijuana flag was waving proudly on Election Day, when Colorado and Washington became the first states where voters approved taxing and regulating marijuana for adult use. Two recently introduced pieces of federal legislation would protect medical marijuana states from federal interference and end federal marijuana prohibition.
As can be imagined, the April 20 celebrations across Colorado and Washington, as well as other "marijuana friendly" states like California and Oregon, will be joyful, well attended and burgeoning with cannabis products. It might even feel as if marijuana is already legal -- but it isn't, and, in some states, the need for secret codes is still very much alive.
In Oklahoma, manufacturing hash carries a mandatory two-year prison term but can also mean life in prison. Under Louisiana law, a second pot possession conviction is classified as a felony offense, punishable by up to five years in prison. Three-time offenders face up to 20 years in prison. And in Florida, possession of more than 20 grams of marijuana, as well as the cultivation of even a single plant, is a felony offense and punishable by up to five years in prison and a $5,000 fine.
What this means, despite Colorado and Washington, is that April 20 brings a chance to stop and reflect on the draconian marijuana laws still threatening so many Americans.
In addition to the lives harmed by arrests and incarceration, the economic costs of prohibition are enormous. The war on drugs has cost at least $1 trillion since it was announced in 1971 by President Nixon.
The term 420 began as a secret code. But 40 years later, in some states the need for a code has given way to "cannabis pride" and open celebration. In other places, people will smoke or otherwise consume pot in private parties. And for those in prison and jails and for their loved ones, it will be just another sad day.
Make this April 20, as the numbers of pro-legalization supporters swell, the day to join the Drug Policy Alliance in promoting the legalization of marijuana for all adults and an end to the war on drugs.
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The opinions expressed in this commentary are solely those of Amanda Reiman.