Most shootings aren't mass shootings. Mass shootings are commonly committed by emotionally or mentally ill persons, a lot like serial killers.
Statistically, most legitimate civil defense with a firearm never results in even the discharge of the weapon.
Concerning DC, NYC and Chi-town, I believe the powers that be might be shocked by the numbers of normally law abiding citizens that own firearms in those cities.
No disrespect LEOs, but citizens have no legal or Constitutional right to expect LEOs to provide safety or prevent crime, individuals are responsible for their own safety. Besides, civilians are usually the first responders in most emergencies.
