] IMAGINE THAT your friendly local mail carrier, before
] delivering a letter for you, decides to steam it open and
] read its contents. An outrageous and illegal infringement
] on your privacy, obviously. But a federal appeals court
] in Boston has just permitted an Internet service provider
] to engage in exactly this kind of snooping when the
] message is sent in cyberspace rather than by snail mail.
] This ruling is an unnecessarily cramped parsing of a law
] that Congress meant to guard, not eviscerate, the privacy
] of communications.

The Post doesn't think highly of this ruling either..

] E-mail has become too ubiquitous, too central a facet
] of modern life, for this ruling to stand.

Derail E-Mail Snooping (washingtonpost.com)