Yeah, an artillery strike, a smoke screen, or fog. I'm also reading the target needs to be stationary or its movements predictable; unpredictable evasive maneuvers should be easy enough to implement (at the cost of speed/range). Plus there's the cost of the device itself, while it says it costs $3 per shot, it's still an (up to) 100 kw device + sensors + power supply setup. It doesn't say how much the system itself costs or its maintenance.