None! Ever!
:grr:
<snip>
Spying on America
But since last week the American public knows better. The news that several major communications companies provided the NSA with more than a billion pieces of data from phone calls and e-mails conjured up the worst Orwellian images of Big Brother. The massive database knows who spoke with whom and for how long. The agency can determine not only which US citizens received a call or an e-mail from places like Saudi Arabia and Afghanistan, the IT spooks with their state-of-the-art computers can also sort through the vast flood of data to identify everyone who has been in contact with them. The system allows NSA officials to develop behavioral patterns, define groups and detect previously undetected connections -- quickly turning a single suspect into hundreds, thousands or even tens of thousands. The pool consisting of data derived from America's long-distance phone connections serves as the basis for deciding who will then be subject to even more scrutiny by the government.
None of this data is destroyed, as millions of new information sources are added to the pool each day. The implication is clear: Someone who may not attract attention today could quickly end up in the sights of the NSA's data miners tomorrow.
http://service.spiegel.de/cache/international/spiegel/0,1518,416136,00.html