Earlier quoted context omitted.
Drones with a paintball gun attached? Realistically that’s going to attract a lot of negative attention.
Just use the drone to spray something on the camera that will etch the glass or destroy the plastic beyond repair.
The advertiser's operators could actually look through the camera and shout through hidden speakers at people vandalising their adverts, usually by writing on the specially-coated toughened vandal-resistant glass that ink or paint didn't stick to.
The local wee wannabe gangsters took to filling bingo markers with the stuff they use to etch frosted glass, and tagging the displays with that.