Tech Dirt 
June 22, 2013
There’s been plenty of commentary concerning the latest NSA leak  concerning its FISA court-approved “rules” for when it can keep data, and when it needs to delete it. As many of you pointed out in the comments to that piece — and many others are now exploring — the rules seem to clearly say that if your data is encrypted, the NSA can keep it . Specifically, the minimization procedures  say that the NSA has to destroy the communication it receives once it’s determined as domestic unless they can demonstrate a few facts about it. As part of this, the rules note:
In the context of a cryptanalytic effort, maintenance of technical data basesrequires retention of all communications that are enciphered or reasonably believed to contain secret meaning, and sufficient duration may consist of any period of time during which encrypted material is subject to, or of use in, cryptanalysis.
In other words, if your messages are encrypted, the NSA is keeping them until they can decrypt them.