Re: Security from whom?
The 3-letter agencies can see your public key, just like any other FB user can. So? How will that help them read messages encrypted with that key?
I thought the same thing but then I thought the post over a little.
I think what the OP is pointing out, is that two parties have access to the cleartext copy. Facebook, and the Facebook user.
Only one of those parties holds the private key: true, so in order to see the message in transit or stored on a server, they need that information. However, nothing stops Facebook technically from sending a copy of the cleartext prior to encryption to a third party.
In other words, one must trust Facebook to uphold the confidentiality of the original message.
This is true of any application of cryptography, and not limited to Facebook or OpenPGP.
Biting the hand that feeds IT
