https://www.pbs.org/wgbh/pages/frontline/homefront/interview...

https://www.eff.org/document/public-unredacted-klein-declara...

https://medium.com/@illicitpopsicle/mark-klein-the-nsa-whist... | https://archive.today/LlZSs

https://medium.com/@chelsealynnqueen94/mark-klein-whistleblo... | https://archive.today/7RlfJ

https://www.youtube.com/watch?v=44edsh6_LUc

https://www.youtube.com/watch?v=KqeMkv5FHfU

(Senator Chris Dodd interviewed Mark, but the video is currently private unfortunately: https://www.youtube.com/watch?v=b9aeKF-rOGA)