He said himself that's what the legal 'justification' was (not the real reason, which was his documentation of anti-genocide protests) - because he admitted to smoking weed while in California (where it was legal at the time) a few years back.

I don't get why people keep posting that tweet in this thread as if it justifies what happened. It's insane, and needs to be addressed.

The tweet is relevant because it refutes the claim that he was denied entry because of a political meme which is what the article implies.

The legality of weed in the US is quite complicated. It is officially still as illegal as ever at the federal level and those laws are the ones that border control care most about. I never said that being denied entry because of that is "fair" or how things should work but it is not entirely unexpected. The US has historically been very hard on drugs and anyone visting ought to know that. It's best not to test the limits of the laws when you are a guest in a foreign country.