Systems and methods are provided for a content aggregation system for intelligent searching of indexed content based on extracted security identifiers. An example method includes obtaining content items from content providers based on authorization information associated with one or more users. Collectors are configured to transform content items into articles representing a normalized form associated with a content item. The method includes obtaining a plurality of articles and storing them in one or more databases. The method includes assigning security identifiers to the articles. A security identifier represents an abstraction of a discrete access right or permission associated with user access to an article. The method includes generating respective indexing messages for execution. The indexing messages are included in a queue and each indexing message includes a reference to an article. A method includes indexing the articles referenced in the indexing messages to enable searching of the indexed articles.