
Here are some of the sources that were mentioned throughout the interviews:
1st question, part 1 - Obama, in Europe, signs Patriot Act extension
1st question, part 2 - Warrantless Spying Skyrockets Under Obama
2nd question - President Obama Signed the National Defense Authorization Act - Now What?
3rd question - Secret 'Kill List' Proves a Test of Obama's Principles and Will
4th question - Drone wars and state secrecy -- how Barack Obama became a hardliner