This is what they've been doing. Taking the fundamental ideas behind Gale's traps and adapting them into weapons against humans. Bombs mostly. It's less about the mechanics of the traps than the psychology behind them. […] Gale and Beetee left the wilderness behind and focused on more human impulses. Like compassion. A bomb explodes. Time is allowed for people to rush to the aid of the wounded. Then a second, more powerful bomb kills them as well.

"That seems to be crossing some kind of line," I say. (13.41-42)