I normally take the ferry back and forth but I do have to drive one day a week to get to my celestial navigation class (GPS is not necessarily reliable these days) in Berkeley.
I'm not sure what security measures they are talking about - I have seen that our local Coast Guard cutters are sporting big guns and sea-whiz doo-dads. I've also seen them doing intimidation approaches to some of my fellow yachters. The bridges have been closed (but are presently open) to foot traffic - not that I think an individual can carry a heavy enough bomb to do damage.
But the most likely scenario (IMHO) is the explosives laden truck that goes off in the far right lane by the suspension cable's lowest point. There is no screening of traffic going over the bridge that I can see (and I drive over all three on thursdays).
I'm getting sick of these fuckers.