It's an interesting article indeed, but I would imagine that if the US government thought it was important enough, they could figure out who's bought marijuana with crypto.  It might be way more difficult than if the weed was paid for via a credit/debit card, but it's possible. 

I'm not sure why this is such a friggin' big issue for Canadians.  It's not like marijuana has gotten any more criminalized in the United States, and I don't see why they should be denying Canadians entry into the states because of pot purchases.  IMO, in this situation cash is still king as long as there aren't other ways of tracking marijuana purchases that the US gov't can find out about.

But hey, I wasn't even aware that marijuana had been made legal in Canada.  I'm not a smoker myself, but I've always supported people's choice to partake in it if that's their thing.  I think that's excellent progress, and thanks for posting the link.