Late last month, a Canadian woman faced a lifetime ban for attempting to cross the U.S. border with cannabidiol (CBD) oil in her possession — the decision was eventually overturned. Meanwhile, recent reports suggest that an American teenager has been arrested for possession of medical cannabis in Russia and could face up to three years in prison if convicted.

Although cannabis is legal in Canada, federal law prohibits Canadians and visitors from crossing the border with the drug — whether entering or exiting the country.

But despite numerous publicity campaigns, signs, press releases, and articles, the hard facts still don’t seem to deter many international travellers.

In the U.S., cannabis is legal in numerous states, but the drug is still classified as a Schedule I narcotic by the DEA and remains federally prohibited. If caught by the U.S. customs, there are bound to be serious legal consequences, regardless of whether cannabis is legal in the U.S. state where the border crossing is located.

Last week, an unnamed 21-year-old Canadian woman was caught with CBD oil in her backpack when she tried entering Washington via British Columbia. She maintains the oil was to treat symptoms of scoliosis. She was fined $500, fingerprinted, denied entry, and told that if she wished to attempt to re-enter the U.S. she would have to apply for a $585 waiver.

The woman’s lawyer, Len Saunders, said that an agent at a U.S. point of entry got in touch to inform her that her case had been reversed and she would no longer have to apply for the waiver.

“My reaction, obviously, was of shock. I was shocked that it was such a 180-degree turn from basically being barred for life to being told that they had on their own reviewed the case and had basically reversed their decision,” Saunders toldCBC News.

But not everyone is this fortunate.

Nineteen-year-old New Yorker Audrey Elise Lorber had 19g of cannabis and a medical permit on her person when she was subject to an airport search in St Petersburg, according to a release from the city court’s press service.

According to the court, Lorber, who was travelling as a tourist with her mother, “kept the narcotic for her personal use.” Although she had a permit, it was only valid within the U.S. and “is not valid on Russian territory.”

Lorber has been charged with possession and remains in custody, awaiting a hearing at a Russian district court.

It appears both travellers believed themselves to be exempt from the laws of the countries they visited as the cannabis in their possession was for medical use, despite the fact that a cursory Google search would have made it immediately clear that this is not the case.

Cannabinoids are federally regulated in Canada, so whether you’re in possession of a THC or CBD product, regardless of whether it gets you high, regardless of whether it’s for medical purposes, regardless of what the laws say about cannabis consumption in Canada — you can not bring a cannabis product in or out of the country, and you are not exempt from legal consequences abroad because the drug is legal in your native country.

Although lax cannabis laws have lulled many North Americans into a false sense of security, spending five minutes doing your homework before embarking on a trip can save you from a lifetime ban abroad — or worse.