Clipper ? - Intel ME
The Intel Management Engine looks to be the modern replacement for the Clipper chip.
Full snooping on the whole memory - internal network capability - able to override the OS - hidden source code (probably only shared with the NSA).
Almost all online Intel based computers with the Intel ME can almost certainly be controlled by the NSA if they wish. Secure encryption and decryption MUST be done on an offline computer with no network connection.