This story is a bit worrying (original ABC News link included). Obviously nobody's going to be easily taking command of passenger planes any more. Could you do serious damage with a ferry boat? Is it the type of ferry that carries a load of cars? If you loaded a car--or several cars--with explosives, who would check for that? Do they have detectors when you board ferries? How hard would it be to take control of one and pilot it to a target on or near the shore? A cruise ship?

Even without explosives, what could a collision do?

Still not all that happy with progress on cargo containers, either.