What think the smart folks of APS?
Complete and utter bovine excrement. I actually mean that. All of the negative assertations are false.
The original "NSA backdoor" in Windows was the whole "NSAkey" thing. Basically, Microsoft made their OS, sent it to NSA to be reviewed for security improvements.
NSA: "You did do a split key, right? So no one person can backdoor Windows by knowing the whole key?"
Microsoft: "Nooo..?"
NSA: "Alright. Generate a new key. Have half signed by person A, half signed by person B. Don't let them share info." (highly boiled down)
Microsoft: "Ok". And names the new key NSAKey, spawning legions of conspiracy theories.
Cue forward.
NSA makes something (actually, pays others to make) SE Linux, which is a cluster of mechanisms for supporting access control security policies. The Windows version is NTFS and Group Policy (kinda, sorta, not a direct parallel). Unix/Linux has been seriously lacking in that area (no joke).
Android is Linux based. NSA ported over the security code. And is working on their own security focused distro of Android, which is open source. ALL of the NSA code is open source, open for scrutiny and worked on by multiple organizations.