There are lots of great benefits to using a smartwatch or fitness band. They can encourage activity, deliver data to you in a convenient and unobtrusive way and they can let you take your music with you without carrying a phone.
But they can also be used to keep spy on people - and that's getting German authorities riled up. An entire class of smartwatches are designed specifically for parents to keep track of their kids. Germany's Federal Network Agency says devices with GPS tracking capability and integrated cellular comms constitute unauthorised transmission systems and have banned the devices.