I was summoned to the search room and ordered to open my suitcase that contained a bottle of champagne. I refused to do so and was told that it would be forced and someone was called for to do so. I responded that I would sue for criminal damage. I waited for some half hour but noone came. I then said that I was being detained against my will and would sue for wrongful detention. The officer responded 'F*** off and take your bag with you. That was three years ago and I've since done eighteen cruises - none with NCL.
The first clue is that your luggage is not delivered and you get a phone call to go to the 'aughtly room'. All impounded luggage is kept there, and you open it in front of them. If they find booze they will take it, and keep it safe for you and return it on the last night. I cannot see the point of smuggling - prices are in US$ which at the moment is so cheapr for us. What is the point of trying to save a few £ (after you have spent thousands on the holiday) by taking on a bottle of £10 vodka which you then drink out of a toothmug, with no ice or lemon. Far better to go to a bar and order one. Just MHO.
The way suitcases are thrown around by airport staff, I wouldn't put alcohol in mine. Also alcohol is generally cheaper abroad anyway.