Beings this feature is currently in the makings of further changes, it should not be too difficult if at all to implement into the game. However, that would be totally up to the tech department to decide. I am only experienced at making a mean ass drink and serving some good shit that can knock an elephant out.

As we all know these NPC's are ambushing us and the reason for their existence is lazy CL's. Which is the minority of the userbase. Why should the entire userbase feel their wrath? If you serve under a lazy CL it is a personal choice.

I suggest those from a city where NPC's show up be forced to sit there and absorb the pain and sufferings from a lazy CL.(s) Instead of avoiding the expense and further hardship involved. The positive side is NPC's will be rid of quicker if their hand is forced to be there. There is no negative side.

My second suggestion would entail anyone who wishes to assist another city ridding of these NPC's only get attacked in a tit for tat style. Not the entire time they are in said city.

Thanks for your consideration.

Not that I can read the mind of Squishy, even if sometimes we poop at the same time thousands of miles away, but I suspect its to annoy the users enough to do the famous "Rank up and do something about it" when it comes to being dissatisfied with the way something is done in game. 

I assume by forced to sit there you mean they can not leave their home city? Issues I see: 

* What if they did not log off in their home city?