Companies like Microsoft and Google store some of their data overseas and when US agencies want access to that data, during a criminal case, for example, they often have a fight on their hands. That's because current laws don't require these companies to provide that data, just as they don't require these companies to hand over data stored in the US to foreign agencies. This has posed a problem on both sides because it can slow down investigations being conducted by US or other countries' officials and it puts tech companies in a sort of legal limbo as they've typically chosen to protect users' privacy since there are no laws compelling them to do otherwise.
However, as the Financial Times reports, the US and the UK are currently hashing out an agreement that would require tech companies based in either country to provide information requested by law enforcement agencies in both the US and the UK. The UK Home Office told the Financial Times, "Since 2015, the UK has been working with the US government, and representatives from US technology companies, on a proposed UK-US bilateral data access agreement that would allow companies in one country to comply with lawful orders for electronic communications from the other." It added, "This agreement would help law enforcement and security agencies protect the public through accessing data stored or controlled by companies in each others' countries in support of serious crime and terrorism investigations, and would include strong safeguards and maintain rigorous privacy protections for citizens."
This data-sharing plan would hinge on laws being changed in the US. Currently the laws governing these situations are around three decades old and were drafted well before email and social media were a way of life. And people from all sides have called for updated regulations. A group of senators have proposed new legislation and tech companies like Apple, Google, Microsoft, Facebook and Amazon have voiced their support for changes in the law through a letter to senators, an amicus brief and speeches. Companies such as Microsoft, Google and Yahoo have all butted heads with the government in court over access to data.