Part 1 of 2. This is an unusual offering by Frontline – an ambitious two-parter on the subject of U.S. secret surveillance efforts, looking into its history, scope and ramifications, from the rise of “The Program” after 9/11 to the whistle-blowing revelations by Edward Snowden (pictured) and beyond. What’s unusual isn’t the scope, or the multi-part investigation. What’s unusual is that, in this case, each part is produced by a different long-time Frontline contributor. Tonight’s Part 1 is by Michael Kirk, and next week’s Part 2 by Martin Smith. Between them, they’ve presented many of the best Frontline entries of this new century, so pay close attention. Check local listings.