The Computers Are Listening - How The NSA Converts Spoken Words Into Searchable Text

Though perfect transcription of natural conversation apparently remains the Intelligence Community’s "holy grail," the Snowden documents describe extensive use of keyword searching as well as computer programs designed to analyze and “extract” the content of voice conversations, and even use sophisticated algorithms to flag conversations of interest... This isn't a technical read but is a good run-down of the progress and challenges facing the intelligence community.