Systems and techniques are provided for managing and categorizing undesired phone calls and text messages. In a specific implementation, an electronic communication identified by a phone number is intercepted at a mobile communications device before the electronic communication is received by an application program on the device. The phone number is sent to a server for the server to identify a category associated with the phone number. The category is received at the mobile communication device. Based on the received category, a determination is made as to whether the application program should be allowed to receive the electronic communication. If allowed, the electronic communication is forwarded to the application program; else, the electronic communication is not forwarded.