In preparation for my first cruise, I have been watching interminable advice videos, vastly most of which cautions are obvious or not appropriate to my lifestyle. One though was of things not to do while cruising in general, and in particular things which will get one ejected. Bringing your own liquor was of that class. I imagine taxation is at the root, beyond mere marketing. Consider the expense of liquor aboard Havila Lines vessels.
I am a bit sensitive to the issue as I usually travel long distances here in the US by AMTRAK, on which liquor is permitted in First Class sleeping car accommodations, but prohibited in coach. Also cannabis is a sensitive issue, occasionally state legal but still prohibited federally.
‘Scanning’ is a red-herring. Thanks for the check in details.