The only thing we've ever been called down and asked to give to security was a dive knife I had on my diving gear. Forgot it was there and would have left it home. They just took it from me and gave it back when I was leaving the ship on my dive and asked me to return it again, which I did. Then they gave it back at the end of the cruise.
But the only thing other than knives you really shouldn't take are irons and booze.
I really don't like cruise lines who go into your luggage and take the items - that's just not right. If they see something on the x-ray, then they should do like most cruise lines do and that's to ask you to come down and open the bag for them. That's the proper thing to do.
Travel Agent/Cruise Specialist w/12 yrs exp and 47 Cruises on 11 cruise lines! Favorites: Paul Gauguin - Tahiti: Uniworld River Cruises - Europe; Celebrity Solstice-class ships; Holland America - 12-nights Baltics & Russia; RCCL - 14-nights Greek Isles, Turkey, & Croatia; Holland America - 14-day Alaskan cruisetour; 10-night Canada/New England cruise; 21 days Hawaii w/7-night NCL cruise; Oceania - 25 days in Asia; more than 3 months touring Europe by train. And many all-inclusive resorts!