@May1 Sorry it was the fines not the signs advising of them. "The reason those cities are unlikely to ever purchase anti-drone technology is that fines for using drones illegally do the trick, and it is generally not necessary to do anything beyond this". .If you feel this is a misrepresentation then I apologise.
Just to repeat. "Unlikely to ever" and "anti Drone technology". Not just dro technology.
There are public spaces which you chose to focus on and then there is/are critical infrastructure , targetted assasinations, cyber/.EMS attacks or even just intelligence collection. Not all bad actors are a group of malcontent youths that want to off a few random infidels.
I would argue that there is greater likelihood of apprehension with your backpack scenario. ( eg Boston) than with the distance afforded by drones especially open sourced home made ones.But that is just a view.
Would failure to protect against a catastrophic event possibly lead to greater losses and litigation over the failure to take steps to prevent such attack than the deaths of a few people due to anti drone measures.(For example the threat of statewide power outages discussed in the paper quoted below. ) Very possibly I would think. You might argue the risk is rare but it is clearly a foreseeable one.
Lets just agree to disagree as I know you need to have the last word. Your triggered personal response kind of forced me to engage.
But my view about the reality of the threat and the need for cities/ states to take steps to protect against same is not an isolated one. :
"The ability of a small group or individual to conduct multiple simultaneous attacks, at a
relatively low cost and with significant standoff distance, will lead to the use of drones as a
primary tactic of future terrorist attacks.... Terrorists have already begun to experiment with the use of drones in
their attacks—it would only take one high-profile attack for all terrorist groups to realize and
exploit this technology. "
https://www.ausa.org/sites/default/files/publications/LWP-137-The-Role-of-Drones-in-Future-Terrorist-Attacks_0.pdf
(20min delay)