Thousands of Canadians assembled on Parliament Hill Saturday as many others gathered in cities across North America to mark the event known as 4/20, the annual rally for the legalization of marijuana.

Bob Erb says he plans to donate $1 million to Canadian marijuana legalization efforts. (CBC)

Activists rallied with renewed optimism this year after two U.S. states — Washington and Colorado — voted to legalize the drug in November.

Gunshots rang out at a rally in Colorado where two people were shot and a crowd of thousands scattered. The injured man and woman were expected to survive.

As well, a British Columbia man who won a $25-million lottery, also in November, said he plans to donate at least $1 million of his prize to the Canadian marijuana legalization movement between now and the next federal election in late 2015.

"I didn't cap it at a million — that's the least I'm going to spend," said Bob Erb, a 60-year-old construction worker from Terrace.

Erb recently wrote a cheque for $125,000 to pay for this year's 4/20 events across the country, including $60,000 on a national website, he said, as well as tents and free hot chocolate on Parliament Hill.

"Education got tobacco smoking from 65 or 68 per cent of the population down to about 18 per cent," Erb said. "They didn't run them through the court system and through the prison system — that's not the way anything should be taught to our youth and society.

"It took 30 years, but look at the results," Erb said.

Eugene Oscapella, a lawyer who teaches drug policy at the University of Ottawa, said Canada is moving backwards in its drug policy.

He said public attitudes are changing and the current system does not work.

"I've been hopeful on many other occasions in my life that we'd actually see some rational drug policy in this country and we've failed to have it so far," he said.

"I've been in this business for 25 years now … I think I realize for the most part that the system we've chosen to deal with drugs, primarily through the criminal justice model and drug prohibition, doesn't work and in fact causes tremendous harm. And so that additional influx of money is going to help to get that message out further."

Erb's $1 million could go a long way with a committed group of people, Oscapella said.

"As Canadians we're not used to donating money to political causes, but also because the drug laws in Canada, though they're bad, they're not as bad as they have been in the United States," he said.

Erb has also donated $7 million to friends, neighbours, charities and people who need help after his lotto win.

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