The same way you defend them against all other sorts of attacks: you make sure the attackers don't get close to the target. Ie: good law enforcement and intelli

The same way you defend them against all other sorts of attacks: you make sure the attackers don't get close to the target. Ie: good law enforcement and intelligence work. For a drone to attack and kill in seconds, you need to basically launch it from the parking lot. If you are bringing weaponry to the parking lot, there are plenty of other (much simpler and cheaper) non-drone-attacks available to you, yet these attacks are really quite rare.