Companies in the United States, when issued a warrant, have been required to hand over all requested data, including anything stored on offshore servers. One of the most prolific examples of this was in 2014, in an incident involving Microsoft. The Justice Department issued a warrant requesting all emails to and from a Microsoft customer who was a suspect in an international drug trafficking case. The company handed over all data stored on US soil, but refused to comply with requests for any data overseas.
The Justice Department, according to this article, fought Microsoft over the data stored in Ireland, pointing out that they were disregarding the court documents that had been issued. According to those documents, the company had to “deliver records, physical objects, and other materials,” on domestic soil. They claimed that since a US company owned and maintained the data, the server location was irrelevant. This was a legal gray area, thanks to the SCA warrant that had been issued.
An SCA warrant, or Stored Communications Act warrant, allows the government to gain access to any domestically held data. This includes emails, text messages, and any other similar electronic data. The DoJ tried to argue that