Although there is nothing in Kermit Lipez's biography to suggest a high level of computer proficiency, his dissenting opinion in the 1st Circuit Court of Appeals case U.S. v. Councilman suggests that he knows what he is talking about. While the majority opinion (which also contains a discussions of MTAs) claims that e-mail intercepted by Procmail recipes do not violate the Wiretap Act, because said messages are in "electronic storage" and are therefore never really "intercepted."
While I am normally reticent about judges attempting to explain the "intent" of lawmakers in their rulings (which forms a large part of the reasoning in Lipez's opinion), I find the majority opinion hard to swallow, especially as it attempts to assign to Congress an intent not to provide electronic communications to the same extent as other forms.
The Wiretap Act's purpose was, and continues to be, to protect the privacy of communications. We believe that the language of the statute makes clear that Congress meant to give lesser protection to electronic communications than wire and oral communications. Moreover, at this juncture, much of the protection may have been eviscerated by the realities of modern technology. We observe, as most courts have, that the language may be out of step with the technological realities of computer crimes. However, it is not the province of this court to graft meaning onto the statute where Congress has spoken plainly.