It was a foggy day with a cloud of marijuana smoke covering over the Vancouver Art Gallery, as more than 10,000 people participated for the annual marijuana smoking event - a rally famously dubbed in marijuana culture as "4/20". This is a day when thousands of people gather in cities, smoke pot and speak on legalising marijuana.

However, parents of young students attending the festival are, perhaps predictably, upset. Parent of two teenagers, Inge Mueller-Langer, was concerned about the situation.

"I don't think it's very responsible. I think the school should instead be educating our children about the potential long-term effects of smoking pot when you are a teenager," Inge Mueller-Langer, a parent of two teenagers told CBC News, "This isn't the same stuff we had in the '60s and '70s."

Shockingly, unexcused absence reports from the Vancouver School Board obtained by CBC News revealed that an additional 900 students missed class on 20 April last year, when compared with Wednesday, 13 April.

"This is not about the war on drugs. It isn't even about marijuana per se," Hilliard, the university spokesman was quoted as saying, "Ten thousand to 12,000 (people) doing anything in the academic heart of the campus would be a problem."

Even with police presence, people at the event openly smoke marijuana and are hardly arrested. Tibor Palatinus, of Narconon, who is a drug expert said students had no business at a public gathering where police stand by as thousands get high.

"It's not a festival," Palatinus said, "It's a pot promotion. It's a weed-selling promotion. Sponsored and promoted by drug dealers. That's what is going on."

Many stories revolve around the 4/20 tradition - one of the more prominent myths is that it supposedly started in the 1970s at a California high school where students would gather at 4:20 pm every weekday to smoke weed. Another one is that the number was a police code for drug usage.

Reportedly sixteen states allow medical marijuana, while two states, Colorado and Washington, are considering legalising it for recreational use.

A glimpse through the Annual Marijuana Rallies...