The ECPA is to protect encrypted information that would require a warrant to gain access to.
The Electronic Communications Privacy Act of 1986 (ECPA Pub. L. 99-508, Oct. 21, 1986, 100 Stat. 1848, 18 U.S.C. § 2510-2522)[2] was enacted by the United States Congress to extend government restrictions on wire taps from telephone calls to include transmissions of electronic data by computer. Specifically, ECPA was an amendment to Title III of the Omnibus Crime Control and Safe Streets Act of 1968 (the Wiretap Statute), which was primarily designed to prevent unauthorized government access to private electronic communications.
The ECPA also added new provisions prohibiting access to stored electronic communications, i.e., the Stored Communications Act,18 U.S.C. §§ 2701-12. The ECPA also included so-called pen/trap provisions that permit the tracing of telephone communications. §§ 3121-27. Later, the ECPA was amended, and weakened to some extent, by some provisions of the USA PATRIOT Act. In addition, Section 2709 of the Act, which allowed the FBI to issue National Security Letters (NSLs) to Internet service providers (ISPs) ordering them to disclose records about their customers, was ruled unconstitutional under the First (and possibly Fourth) Amendments in ACLU v. Ashcroft (2004). It is thought that this could be applied to other uses of National Security Letters.
