My husband and I recently cruised on QE2 and were surprised by the different attitudes towards security when the ship was docked. At Southampton, her home port, you cannot get near the ship unless you are approved by security yet when we docked at Le Havre in France there were locals swarming all over the place, coming right up to the ship and the gangway.
When my husbard asked a member of the security staff why there was such a difference in security measures, she just shrugged and said that different countries had different rules!!
Personally, I feel safer on a cruiseship than I ever would on a plane and I don't think I would ever let the threat of terrorism stop me from cruising!!!