The smoke filling it up can no longer be deemed a reason for arrest in Canada:
“The smell alone can’t constitute the grounds because the smell of burnt marijuana – as opposed to raw marijuana – gives an inference that the material is gone, it’s dissipated into the atmosphere. So how can you say you’re in possession of something that doesn’t exist?” said Ronald Piche, Janvier’s lawyer.
h/t Dorian Gray (from Andrewsullivan)