Another official said those participating in the marijuana business may be turned away at the border. “Facilitating the proliferation of the legal marijuana industry in U.S. states where it is deemed legal or Canada may affect an individual’s admissibility to the U.S.,” Todd Owen, executive assistant commissioner for the Office of Field Operations at the U.S. Customs and Border Protection agency, told Politico in comments published Thursday.

While Owen didn’t specify any minimum level of investment, he signaled the focus was more on those bringing the sector to the U.S., which could have implications for the burgeoning sector. Until his comments, the BI Canada Cannabis Competitive Peers index had gained nearly 50 percent since the Canopy-Constellation deal was announced. Individual stocks have posted more outsized gains, with Tilray Inc. up more than 600 percent since its July IPO.

Seeking Clarity

Canadian Public Safety Minister Ralph Goodale has often said he’s working with U.S. law enforcement to clarify the changes and make sure the border remains smooth. The advice of Goodale and Trudeau is to be honest at the border-- and make sure you’re not carrying.

“Despite one-in-eight Canadians using cannabis today, 400,000 people move between our two countries every day almost entirely without incident,” Goodale spokesman Scott Bardsley said by email. “Officials from the United States have said that they do not plan on changing their questions at primary inspection after cannabis is legalized in Canada.”

The government is also ramping up advertising reminding Canadians of their obligations to obey the laws of both countries. That message hasn’t “fully sunk in” yet especially with more casual tourists, said Continental Travel Group President Daryl Silver.

Too much zeal by border agents could encourage even more Canadians to stay home, at a time when President Donald Trump is targeting the country in trade negotiations. “We already notice somewhat of a trend of some people not going to the U.S..” said Silver. “This could add to that.”

Canadians spent $19.8 billion on tourism south of the border in 2016, according to the International Trade Administration. The figure was $27.2 billion in 2014 when the country’s currency was close to par with the greenback.

‘Caught by Accident’

“People are careless and I think people will be caught by accident and this will create problems,” said Lorne Waldman, an immigration lawyer. “No lawyer could counsel anyone to lie to a border agent, but if an agent asks the question, I suppose they could decline to answer.”