If simply telling a U.S. border guard that you have smoked pot can get you barred from the country for life, then many who have never been asked the question might be wondering what prompts a customs officer to pose the query in the first place.

That was certainly on the mind of Vancouver's Alan Ranta, 35, a freelance music journalist, when he attempted to drive his Toyota Yaris hatchback from British Columbia to Washington state in July to cover the Cascadia music festival.

"[The U.S. border agent] didn't like the look of our camping gear, I guess," said Ranta. "He just asked us two questions: Where we were going, and if we were hiding anyone in the back."

U.S. border agents searched his car and found a purse that read "weed money," which Ranta says had never contained pot or money.

"I answered truthfully. I said I had smoked [weed]," he said. "That led to followup questions on how much I smoked, where had I smoked it and when I smoked."

After that he was denied entry and told that he was barred from the country for life. To ever get back into the U.S. he would have to apply for a $585 US ($752 Cdn) travel waiver.

Ties to the marijuana industry

On Thursday, CBC News reported on the case of another Canadian, Matthew Harvey, 39, also of Vancouver, who is facing the same fate as Ranta after telling a U.S. customs officer he had smoked pot after he turned 18 but before he had obtained a medical marijuana license.

After that story ran, CBC News learned Harvey also has a well-documented career working in B.C.'s marijuana industry, including at the B.C. Bud Depot, a producer and worldwide seller of marijuana seeds, according to its website.

The company's Facebook page boasts several photographs of Harvey, and the company's YouTube channel shows a video of him accepting a Cannabis Cup award at a marijuana event.  A 2014 press release from Cavan Ventures, a Vancouver-based company with an interest in medical marijuana, announced Harvey's appointment to its advisory board by describing him as a "master grower."

Reached Friday, Harvey said that while he works in the industry, that was not the reason he was flagged at the border. His attorney, Len Saunders, an immigration lawyer with a practice in Blaine, Wash., who is also representing Ranta, said that according to the documents he received from the U.S. government, Harvey's links to the marijuana industry had nothing to do with him being barred.

Drawing attention at the border

But Fadi Minawi, a Toronto-based lawyer with Niren & Associates that specializes in Canadian and U.S. immigration law, said there are any number of reasons why someone may be flagged for extra attention at the border.

Minawi said people attending music festivals, going to Las Vegas to party, business people travelling frequently between Canada and the U.S. or someone with a past customs violation could also prompt extra attention at the border where they might be asked if they smoked pot.

He said he even represented someone detained on their way to an NFL tailgate party across the border who was asked the pot question and was then barred after giving a truthful answer.

In the last two years, Minawi said, his office has received inquiries from at least 50 people who have been barred from the U.S. for life after telling a U.S. border agent they smoked pot. Some employ his services; others, he said, are put off by the prospect of a drawn-out legal battle and simply agree to pay the travel waiver fee.

Eugene Oscapella, an Ottawa lawyer who teaches drug policy at the University of Ottawa, said that an online presence in the marijuana industry or any association with drugs could easily cause you to be flagged at the border. He cited the case of Vancouver psychotherapist Andrew Feldmar.

In 2006, Feldmar was turned away from the U.S. border and barred for life after a border guard searched his name on the internet and found that he had written in an academic journal about using LSD in the 1960s.

"They can ask whatever questions they want," Oscapella said. "If they think playing checkers is bad, they can go ahead and ban us for playing checkers."