Sneaking Alcohol onto a cruise ship

First off, this isn't a continuation on the debate about whether it's right to sneak alcohol onto a cruise ship or not. That debate's been done several times in the past and I don't think either side are ever going to agree with each other.
From my point of view I can see two main reasons for bringing alcohol onboard yourself. Firstly, you fancy a quite drink in your cabin before you go out or as a night cap without having to wait for room service or walk all the way to a bar yourself. The second reason is that you have decided the cruise lines prices for drinks are too expensive so you bring your own booze to get drunk in your cabin before going out for the evening.