1. A non-transitory computer readable medium having stored thereon instructions executable by a computing system to carry out functions for panel-based management of data comprising: receiving data objects from a plurality of sources, and storing the received data objects, wherein each data object defines a record of information regarding at least one of a device event and a device state, and wherein each data object has a timestamp; storing a plurality of panels each defining a respective association with a set of the received data objects, the plurality of panels including at least one of (i) a time-based panel defining an association with received data objects based on timestamps of the received data objects and (ii) a subject-matter panel defining an association with the received data objects based on subject matter of the received data objects in accordance with a subject-matter filter of the subject-matter panel; causing a display of a device to display a graphical user interface having at least: (a) a general data-feed component for presenting indicia of the received data objects, wherein the indicia of the received data objects presented in the general data-feed component are selectable to cause the display to present respectively indicated data objects, (b) a panel-presentation component for presenting indicia of previously created panels, wherein the presented indicia of the previously created panels include, for each of the previously created panels, presentation of an indicium of a set of received data objects associated with the previously created panel, and (c) a panel-definition component for receiving commands to create new panels and to further define the previously created panels, for presenting indicia of items selectable to be used as a basis to define a subject-matter filter respectively for any panel, and for receiving selection of one or more of the presented indicia, wherein the items comprise (i) one or more of the received data objects and (ii) one or more semantic objects extracted from the received data objects, and wherein a command to create a new panel is by default a command to create the new panel as a time-based panel unless and until a particular subject-matter filter is defined for the new panel; receiving data corresponding to input defining one of the commands to create a new panel received through the panel-definition component, and responsively causing the display to present the new panel as a time-based panel to be populated with indicia of any data objects received by the computing system while the new panel is being displayed; receiving data corresponding to input representing the selection of one or more of the presented indicia of the items to be used as the basis to define the subject-matter filter for a first panel, and responsively defining the subject-matter filter for the first panel based on one or more attributes of one or more items whose presented indicia were selected; and determining that one or more of the received data objects defines a record that a user device presented particular information at user request, and responsively identifying an attribute of the particular information and automatically creating and storing a second panel having a subject-matter filter keyed to the identified attribute.