The US government has affirmed its longstanding antagonism to employee and citizen privacy in electronic communications. Contrary to rules for snail mail and phone conversation, employers can take what they want, when they want. Government wants the same ability. Their arguments follow a 40 year long chain of faulty reasoning and malicious intent designed to overturn Katz vrs the US.
On October 8, 2007, the United States Court of Appeals for the Sixth Circuit in Cincinnati granted the government's request for a full-panel hearing in United States v. Warshak case centering on the right of privacy for stored electronic communications.
... the position that the United States government is taking if accepted, may mean that the government can read anybody's email at any time without a warrant. The most distressing argument the government makes in the Warshak case is that the government need not follow the Fourth Amendment in reading emails sent by or through most commercial ISPs. The terms of service (TOS) of many ISPs permit those ISPs to monitor user activities to prevent fraud, enforce the TOS, or protect the ISP or others, or to comply with legal process. If you use an ISP and the ISP may monitor what you do, then you have waived any and all constitutional privacy rights in any communications or other use of the ISP.
What's needed, of course, is more protection not less. Previous failures do not excuse future violations. Government violation of privacy costs money and spending money that way is outrageous. They should instead spend them money prosecuting companies that violate user privacy or block communications. Half of the government's argument would fall apart if ISPs permitted people to run their own mail servers. The other half falls apart in the face of widespread encryption. All of it is wrong and that should be enough for them to lose, but there's little hope of that.