If we accept that an email is analogous to a letter or a phone call, it is manifest that agents of the government cannot compel a commercial ISP to turn over the contents of an email without triggering the Fourth Amendment. An ISP is the intermediary that makes email communication possible. Emails must pass through an ISP's servers to reach their intended recipient. Thus, the ISP is the functional equivalent of a post office or a telephone company. As we have discussed above, the police may not storm the post office and intercept a letter, and they are likewise forbidden from using the phone system to make a clandestine recording of a telephone call—unless they get a warrant, that is. See Jacobsen, 466 U.S. at 114, 104 S.Ct. 1652; Katz, 389 U.S. at 353, 88 S.Ct. 507. It only stands to reason that, if government agents compel an ISP to surrender the contents of a subscriber's emails, those agents have thereby conducted a Fourth Amendment search, which necessitates compliance with the warrant requirement absent some exception.
In Warshak I, the government argued that this conclusion was improper, pointing to the fact that NuVox contractually reserved the right to access Warshak's emails for certain purposes. While we acknowledge that a subscriber agreement might, in some cases, be sweeping enough to defeat a reasonable expectation of privacy in the contents of an email account, see Warshak I, 490 F.3d at 473; Warshak II, 532 F.3d at 526-27, we doubt that will be the case in most situations, and it is certainly not the case here.
Complete with photos, names, titles, of the 41 federal department and independent agency CIOs. The March 2015 Insopector General report linked from the article belies Hillary Clinton's claim that all emails she sent to State Department staff had been preserved by the Department.