Oh, I don't doubt that at all. I know of at least one time when the Coast Guard locked down the entire channel, from Galveston to Houston, for about three days. Never saw anything in the news about it though. I only know this because one of the ships we were waiting on got waylaid at Galveston because of it. In fact, a lot of the ships we work with have been delayed by the Coast Guard. Which is good. Also, we've noticed the helicopters that patrol the channel have been unusually active. Maybe a month ago, we watched one fly up and down the docks (from about #25 on up). Dunno what that was all about, but they were obviously looking hard at something. A day or two later, we watched two (which is rare) do something unprecedented; they each, in turn, landed and took off near the 'cop shop' there at the port. I don't know what to make of all that, but I can tell you this: security at the port has been very busy these days.
It's almost ironic you would mention the bridge. That weakness has been known for a long time. IIRC, it was even mentioned publically at one point. This is my own wild speculation, but I think that was a lure of sorts.
They could hurt us anywhere from The Houston Yatch Club up through pipelines leaving the city heading north.
Yes, that is a lot of ground to cover.
Instead, all we hear is about how many Americans have died in Iraq.
There could (should) be some great disaster/horror films made about terrorist plots