I can't really remember how long ago it was, but I think the book was marketed towards children/teens. All I remember is the basic premise of the story.
Some story about these unusual little blue electric critters that only certain people could see, and these kids took it upon themselves to go about destroying them since they fed off energy or something like that. Not sure whether they fed off people or off electricity... or both maybe? I think the dominant method of destroying them was an electric baton that was taken from law enforcement. I wanna call them buzz batons, but that's probably thanks to Artemis Fowl.