Councilman Amicus Brief:
In news relating to the recent First Circuit wiretapping decision in United States v. Councilman (previous posts here and here), a coalition of privacy groups including the Center for Democracy and Technology, the Electronic Frontier Foundation, the Electronic Privacy Information Center, and the American Library Association have just filed an amicus brief in favor of the goverment's petition for rehearing. The brief is available in .pdf format here.
For reasons that become clear once you read the cover page, I think the brief is very persuasive.