Aleksandar Andjic / EyeEm

The US and UK signed an agreement Thursday that will allow law enforcement officials in both countries to demand tech companies in the other's country to furnish electronic evidence for use in criminal investigations. The agreement is the first approved under the controversial CLOUD Act passed by Congress last year.

The agreement between the two counties "will dramatically speed up investigations by removing legal barriers to timely and effective collection of electronic evidence," the US Justice Department said in a statement. The pact will allow investigators to gain access to data on serious crimes such as terrorism, child sexual abuse and cybercrime without encountering legal obstacles.

"Only by addressing the problem of timely access to electronic evidence of crime committed in one country that is stored in another, can we hope to keep pace with 21st Century threats," US Attorney General William Barr said.

The CLOUD Act, which stands for Clarifying Lawful Overseas Use of Data Act, updated the rules for criminal investigators who want to see emails, documents and other communications stored on the internet. It also lets the US enter into agreements to send information from US servers to criminal investigators in other countries with limited case-by-case review of requests.

The pact replaces current process for sharing internet user information between countries, called MLAT, or a mutual legal assistance treaty, which requires law enforcement officials to get court authorization before going to tech companies. That process often takes years, the Justice Department said.

But privacy advocates at groups like the ACLU and the Electronic Frontier Foundation criticized the change, saying it lets law enforcement bypass constitutional protections against unreasonable searches. It also could lead the US to send user data to police in countries known for abusing the human rights of their citizens, they argue.