An alert from the TSA. "Government warns of terror threat to trains," by Jim Popkin for NBC News :
In a bulletin released Friday to U.S. law enforcement officials, the Transportation Security Administration (TSA) is warning of “continued strong terrorist interest” in targeting mass transit systems in the U.S. The 10-page threat assessment, labeled “Unclassified/For Official Use Only” and obtained by NBC News, cautions that the “U.S. mass transit and passenger rail systems are vulnerable to terrorist attacks because they are accessible to large numbers of the public and are notoriously difficult to secure.” Previous rail attacks in Madrid, London and Mumbai “could inspire terrorists to conduct similar attacks in the United States,” the report adds.
However, the authors of the intelligence analysis make clear that there are no known, immediate dangers. “At this time, there is no credible intelligence regarding specific plans by any extremist groups or individuals to perpetrate an act of terrorism against the U.S. mass transit system,” they write.
"Mass Transit System Threat Assessment"
The report is titled the “Mass Transit System Threat Assessment” and was prepared by TSA’s Office of Intelligence. It comes just weeks after Amtrak announced a series of new security measures. Amtrak does not routinely screen passengers or their baggage with metal detectors or other devices, as all U.S. airlines do. Instead, it announced on Feb. 19 that it would use so-called Mobile Security Teams to randomly check passengers and baggage.
The report identifies Al-Qaida as one of the “most likely actors” in potential attacks. “Al-Qa’ida and affiliated extremists pose the greatest threat to the U.S. mass transit and passenger rail system,” it states. “The threat to heavy and commuter rail in the Homeland is greater than the threat to buses and light rail. Attacks on buses overseas tend to be small-scale and are carried out mainly by smaller separatist groups within their own countries.” Other terror groups are a threat, too. “Lebanese Hizballah, which has supporters inside the United States, is less likely to attack U.S. domestic interests unless it perceives the United States has become a direct threat to its leadership, its armed capabilities, or to Iran,” the TSA authors write.