Things don't have to be jam-proof, but the processes that depend on them should have a sensible failure mode. If anyone with a small backpack filled with fairly

Things don't have to be jam-proof, but the processes that depend on them should have a sensible failure mode. If anyone with a small backpack filled with fairly cheap jamming equipment can disrupt hundreds of systems in a busy area, then society (emergency services in particular) should know how this disruption can be prevented or mitigated, and also what the cost of such disruption would be (i.e., is it merely economical, or are human lives at stake?). Preferably before we become too dependant on such technology.