Methods, systems, and apparatus, including computer programs encoded on computer storage media, for managing sensor communications in a monitored environment. One of the methods includes receiving, by a server and from a device that is accepted to connect with a first network using acceptance data that includes a first key indicating the device is associated with the first network, a request a) to join a second network different from the first network b) that identifies the first key; determining, by the server and using the identification of the first key in the request, that the device that transmitted the request is associated with the first network; and providing, by the server, an notification i) to a user associated with the first network ii) indicating that the device has moved outside the first network.