Security systems may include sensing, networked communications, stealth, alarms, and countermeasures, any or all of which may adapt to threats. These systems may also include armor and barriers of concrete and/or steel. They can adapt to severity of threats, weather, and/or other situational aspects. They can anticipate at least some threats in order to obtain early warning and react more quickly to those threats. They can adapt by altering their configurations, including alterations in communication networking structures and methods, and changes in data-storage and processing duties at processing nodes. Defensive and/or offensive countermeasures can be employed to deter, confuse, trap, and/or disable terrorists. The systems are capable of self-maintenance, self-healing, and self-restoration as threats subside. The systems can include subsystems capable of autonomous operation. At least some of the systems and/or their subsystems are capable of allocating power among subsystems, and of regulating bandwidth utilizations.