Cruise magnets.
Cat T mid ships, had ours stolen regularly, but not by kids as mentioned. After a few had gone, we heard a noise outside our door, looked through the eyehole, it was adults doing it. I put stateroom numbers on ours, they didn't spot they, when I found them on another decks stateroom door.
Stateroom tour!
Again Cat T Magic, embarkation, we were allowed in our room at 1 pm, general, stateroom opening was 1.30 pm. There was an issue in our room, so maintenance were in, our door propped open as they went in and out. We were in the room.
I heard a male cruisers voice at 1.30 opening, " let's look inside the suite", he was coming in with his family, as he got through the hallway, I looked at him, he did a cartoon style, about turn and quickly went out. Why do cruisers have entitlement to think they can go in a stateroom that's not theirs to have a look around?
Ringing bells.
Same Cats, there are a few who do, knock down ginger, ring the doorbell and run, again in our experience it's adults, not kids.
Bring your own booze.
Baltic, 2015, a group of adults bring on too much booze, including Russain Vodka, they had thier own deck party, after hours, pool deck, and D Lounge. Drinking, loud, throwing up, leaving trash for DCL to clear up. We now know why DCL changed its policy. PS Do not drink Russain Vodka, unless your use to it.