What's the difference between a subpoena, a search warrant and a court order under ECPA? And what information can a government agency get from Google with each?
It's complex, but here's a summary of the different forms of legal process covered by ECPA:
Subpoena Of the three types of ECPA legal process for stored information, the subpoena has the lowest threshold for a government agency to obtain. In many jurisdictions, including the federal system, there is no requirement that a judge or magistrate review a subpoena before the government can issue it. A government agency can use a subpoena to compel Google to disclose only specific types of information listed in the statute. For example, a valid subpoena for your Gmail address could compel us to disclose the name that you listed when creating the account, and the IP addresses from which you created the account and signed in and signed out (with dates and times). Subpoenas can be used by the government in both criminal and civil cases. On its face, ECPA seems to allow a government agency to compel a communications provider to disclose the content of certain types of emails and other content with a subpoena or an ECPA court order (described below). But Google requires an ECPA search warrant for contents of Gmail and other services based on the Fourth Amendment to the U.S. Constitution, which prohibits unreasonable search and seizure.
ECPA Court Order Unlike an ECPA subpoena, obtaining an ECPA court order requires judicial review. To receive an ECPA court order, a government agency must present specific facts to a judge or magistrate demonstrating that the requested information is relevant and material to an ongoing criminal investigation. With such a court order, a government agency can obtain the same information as a subpoena, plus more detailed information about the use of the account. This could include the IP address associated with a particular email sent from that account or used to change the account password (with dates and times), and the non-content portion of email headers such as the "from," "to" and "date" fields. An ECPA court order is available only for criminal investigations.
Search Warrant The threshold is higher still for an ECPA search warrant. To obtain one, a government agency must make a request to a judge or magistrate and meet a relatively high burden of proof: demonstrating "probable cause" to believe that contraband or certain information related to a crime is presently in the specific place to be searched. A warrant must specify the place to be searched and the things being sought. It can be used to compel the disclosure of the same information as an ECPA subpoena or court order—but also a user's search query information and private content stored in a Google Account, such as Gmail messages, documents, photos and YouTube videos. An ECPA search warrant is available only in criminal investigations. The video below provides an overview of how we review and respond to ECPA search warrants.
