Source: Wired - Threat Level
1) The NSA generally destroys communication of U.S. persons that are collected incidental to collecting data on foreign individuals — unless the communication is encrypted...
2) The NSA maintains a massive database of U.S. email addresses and phone numbers...
3) The NSA also maintains a database of information incidentally collected from GSM and Home Location Registers...
4) When the NSA does pick up purely domestic communications, it can still use or pass the intercepted call or email to the FBI or other federal agencies if there is evidence of a crime or a national security leak...
5) If the NSA intercepts data between an attorney and client, it will still be retained...
