Living in France as I do, I remember the Madrid bombings vividly. And having a "summer term abroad" daughter one stop away from King's Cross at the time of the London bombings was scary and sobering. France has had to shut down its trains and inspect all of its thousands of miles of tracks because of bomb threats (and French authorities did, in fact, find explosives along its train lines).

Does the same level of threat exist in the U.S.?

No easy solutions here. I'm not looking forward to random searches (when I'm in the States, I use Amtrak to shuttle between family in LA and San Diego). I will be surprised if a system can be set up in such a way as to not create delays.

The bigger issue, as has been noted above, is security v. privacy rights. TSA is out of control when it comes to airline "security," and I shudder to think that TSA is now going to extend its extra-Constitutional powers to train travel.

I lived in Tarzana from 4th grade onwards. (When non-Los Angelenos laughed at the funny name, I used to tell them Edgar Rice Burroughs could have called it "Cheetahville.")

Just wanted to say that there was always a big difference between the Tarzana north of Ventura Boulevard and that south of the boulevard: different school catchment areas, different topography, different feel and layout. The orchards and farms north of the boulevard are now more and more carved up into subdivisions with houses far too grandiose for the tiny lots they stand upon; the area south--the wealthier part of "Tarzana Ranch," where celebrities still live, has encroached higher and higher into the hills (far above and beyond the now-old subdivision of "Deauville").

A lot of good stuff was on its way out when I got married and moved away... some 25+ years ago.