1. A computer-implemented method comprising: determining, by a computing system, a source of a first content item; determining, by the computing system, that the source previously published at least one second content item that was determined to be rendered incompletely when presented; capturing, by the computing system, a screenshot image of a display interface while the first content item is being presented; and determining, by the computing system, whether the first content item was rendered incompletely based at least in part on the source of the first content item and the captured screenshot image.