In some implementations, each of the video sources 222 includes one or more video cameras 118 or doorbell cameras 106 that capture video and send the captured video to the server system 164 substantially in real time. In some implementations, each of the video sources 222 includes a controller device not shown that serves as an intermediary between the one or more cameras and the server system 164. The controller device receives the video data from the one or more cameras, optionally performs some preliminary processing on the video data, and sends the video data to the server system 164 on behalf of the one or more cameras substantially in real time. In some implementations, each camera has its own on board processing capabilities to perform some preliminary processing on the captured video data before sending the processed video data along with metadata obtained through the preliminary processing to the controller device and/or the server system 164. In accordance with some implementations, each of the client devices 220 includes a client side module. The client side module communicates with a server side module executed on the server system 164 through the one or more networks 162.