The Circle with Disney ($99) device is this small 3.25 inch cube whose rechargeable internal battery means it can't be deactivated by children. How does it work? Circle with Disney isn't a router but uses your existing internet setup. It employs "ARP spoofing," a technique that can be used to hack networks, to actually safeguard your WiFi. As your data moves between home devices and your router, it's redirected to this device for encryption and monitoring.