here's what's going down on the waterfront in my town:

i'm a deckhand on tourist cruises and ferry boats on the SF bay. we've been undergoing USCG training for security purposes. vigilance and immediate notification of suspicious behavior are stressed. periodic boat sweeps and (locked) securing of bomb-stuffable areas are stressed. the fact that we are the 'first line of defense' is stressed (ergo, you're all doomed, ha ha ha)...but we do keep our eyes open for anything weird, true.

still, there's really nothing to stop armed maniacs from taking over our boat and ramming it into an oil tanker or who knows what. smuggling backpacks of explosives onboard would be tougher but it of course could be done. we're also told to keep an eye out for people videotaping our activities from the pier, but that's nearly impossible to keep track of; there're tourons constantly shooting video of us, from all angles. plus, if someone wanted to take notes and video of our schedules, MO and tendencies, they could do it from the outside deck of the pier cafe on the second floor, with the screen of their tiny vidcam set so that they wouldn't have to have their eyes glued to it while they sat and ate for an hour.

it needs be said that there certainly is an element of ass-covering ('at least we did something') in the terror alerts - but any party in power would do as such.

all in all, it's nice to suggest vigilance - and it can make a difference - but the truth remains that there is no defense against people willing to die. basically, we'll do what we can (and we will), but if maniacs want to fuck shit up, they can. to a large extent, we will have to learn to live with it, unless we get so freaked that we either demand or allow ourselves to be put into a complete police state...and then they've won, pure and simple.

i don't have an answer for this challenge, other than 'we'll do what we can'.