"...then Bud made himself scarce, because the monitors - almond-sized aerostats with eyes, ears, and radios - had probably picked up the sound of the explosion

"...then Bud made himself scarce, because the monitors - almond-sized aerostats with eyes, ears, and radios - had probably picked up the sound of the explosion and begun converging on the attack. He saw one hiss by him as he rounded the corner, trailing a short whip antenna that caught the light like a hairline crack in the atmosphere. Aerostat meant anything that hung in the air. This was an easy trick to pull off nowadays. Nanotech materials were stronger. Computers were infinitesimal. Power supplies were much more potent...a device built with several thrusters pointed along different axes could remain in one position or indeed navigate through space." - The Diamond Age, by Neal Stephenson (1995)