See the latest fallout from choosing a cannabis brand that too-closely matches an existing non-canna trademark: http://mjbizdaily.com/under-legal-pressure-seattle-mj-retailer-changes-name/

While we can't say that the replacement brand was much of an improvement ('pot shop' is descriptive and therefore difficult to protect), at least they are straying from the well-worn industry brand tropes (stash, green, canna, kind, etc.). In this case, re-branding was the responsible choice, and should serve this company better in the long run. A reminder not to get too attached to your weak trademarks.