I have often wondered why this did not come up sooner. With 233,000 miles of track, the number of vulnerable spots as described must number in the few thousands, somewhere between 3000 and 5000, I would guess.
Metropolitan areas are covered, but in open country there is an enormous vulnerability.
Web cameras exist for watching border areas on the internet that anyone can access and monitor. Perhaps a similar system can be installed in all critical remote areas that can be be active 24/7 and monitored by volunteers. Shut-ins, retired people, insomniacs, the list is endless. I hate to even imagine creating an army of unionized high paid morons to do the job. With each camera identified on screen, the reporting of suspicious activity can be reported to a central location in seconds.
The same can be done to a few other similar critical items of infrastructure that need not be listed or discussed here, but which would profit from round-the-clock surveillance.
IIRC, there was an Amtrack derailment some years back blamed on some white-guy fringe group. Not sure, but it may have been during the Clinton Regime. They consistently downplayed ROP involvement in ‘man-made disasters’.