Southern Californians can feel trapped on a freeway in gridlocked traffic. One of the San Bernardino shooters and his longtime friend talked about taking advantage of this vulnerability by launching a terrorist attack on a clogged freeway using guns and pipe bombs, reports the Los Angeles Times. Syed Farook and Enrique Marquez mapped out the attack plan in detail and collected weapons and explosives in 2011 and 2012, only to abort the plot, say federal charges. Their outlandish alleged scheme has counterterrorism experts both alarmed and baffled. Experts say such an attack would be feasible, but some questioned the seriousness of the plot, given that there are so many easier ways for shooters to cause mass casualties.