They could use cameras, microphones, motion sensors and thermal imaging
They would send a message to the parents and give children a verbal warning
The system could use this real-time information to decide when to discipline

Read more and see video on: http://www.newtribeng.com/science/google-big-brother-style-system-that-uses-cameras-and-sensors-to-watch-your-kids-and-tell-them-off-when-theyve-been-misbehaving/