[RajT88]

Build a detector which can differentiate from normal traffic and a "scan" like this.

Wire up an RPI to a motor which reorients a 2.4ghz parabolic dish, first discovering the direction and elevation which best picks up the signal from the "scanner". Then, engage the old microwave emitter you've hooked up to the dish.

You will like as not fry their equipment. Bonus: the attacker may never have children.

[samus]

That's the best part of it: the technique seems to be passive.

[RajT88]

Fry everything then.