The side effect is killing Fire Fighters not part of military personnel. If it's IEDs placed, that require the same skills as placing Graffiti in a public transport system, they might even turn target or victim to delayed follow up explosions needed to increase the physical damage.
Protecting them is hard for an attacker, but easy for the defender.
Just have them build more of exactly those concrete barriers they use to hide hearing the Drones engines.
Railway systems are harder to protect, but can create even more collateral damage in times in which trains can have 200 humans loaded.
Separating tracks and upgrading the entire system is easy and increases the attraction of the railway still most important system of masstransport.
Every efficiency upgrade in a railway system must come based on increased system safety having the side effect of limiting sabotage attacks down to damage on steel, stone and soil parts of the system.
Fighting conflict can increase progress not conflict as such.
#MIB
