Let's also bear in mind that London has had plenty of experience with Tube bombings by the IRA back in the 70's and 80's. Their camera surveillance systems in both the Tube and all around public areas have been a normal fact of life there for years now, and are hardly commented on. I have friends in London, and their comments to me were basically along the lines of "It happened, it is a shock, but we just keep going on...we're used to the possibility of something happening but don't dwell on it."
And that's MY problem...while London and other European countries (not to mention Israel) keep on with their lives, and QUIETLY (without any media attention and fanfare) increase their security, we here in the U.S. broadcast to the whole world HOW we're increasing security, WHEN we're doing it, and WHERE we're doing it. No wonder we can't catch anybody, they're all watching CNN as well and know when we're coming!
*stepping off my soapbox and returning to the sane world of railroading now*....
"CSX Detector. Milepost Six Point Four. No Defects. Repeat: No Defects. Total Axles Seven Four Seven. Detector Out"