In this case, it's going to be kept secret and covered by some kind of "security clearance". That would make it a criminal offense to divulge these details. The law explicitly limit this to the "meta data" of the communication, and not the content.
And finally, publishing these details would defeat the whole purpose of the enterprise. The NSA does not publish details about the meta-data they collect in the PRISM database, and they charged the Snowden for the little that he revealed about the program.
The French are essentially doing the same thing. The NSA has some limitations about when US citizens meta data can be collected domestically. The French law has no such provision.
Take everything, analyse later, break crypto even later.
If encrypted or not, doesn't matter to these folks. Their buddies at GCHQ do the same, remember?