Privacy Digest reports on a new White House proposal to extend the powers of FBI "national security letters" to include gathering of "electronic communication transactional records". While this may appear to be a small change, the potential impact is huge.
These records include all the header information from emails: To:, From:, Time, and often Subject:.
It may also include a list of the full URLs that you visit.
While it does not include the contents of the messages, this level of detail is often more than enough to discover social networks, relationships, intentions, plans, political affiliations, and more.
The real problem is that there are no checks and balances on national security letters. They are issued by FBI offices on their own authority without review by a judge. Historically, self restraint in the face of this kind of power has never worked well. While judges approve the vast majority of subpoenas and search warrants in a timely manor, they can reject egregious cases and the mere fact of their review causes law enforcement to be more restrained in their use.
From the Privacy Digest article:
The use of the national security letters to obtain personal data on Americans has prompted concern. The Justice Department issued 192,500 national security letters from 2003 to 2006, according to a 2008 inspector general report, which did not indicate how many were demands for Internet records. A 2007 IG report found numerous possible violations of FBI regulations, including the issuance of NSLs without having an approved investigation to justify the request. In two cases, the report found, agents used NSLs to request content information "not permitted by the [surveillance] statute."