"Law enforcement officials in the United States and abroad increasingly seek access to electronic communications, such as emails and social media posts, stored on servers and in data centers in foreign countries. Because the architecture of the internet allows technology companies to store data at a great distance from the physical location of their customers, electronic communications that could serve as evidence of a crime often are not housed in the same country where the crime occurred. This disconnect has caused governments around the world, including the United States, to seek data stored outside their territorial jurisdictions. In the Clarifying Lawful Overseas Use of Data (CLOUD) Act, Congress enacted one of the first major changes in years to U.S. law governing cross-border access to electronic communications held by private companies."
CRS Report for Congress, R45173