The US House of Representatives approved late Thursday a bill that would restrict the electronic surveillance powers of the National Security Agency (NSA).
The margin was wide, 293 to 123, for the bill attached to the defense budget for 2015, which begins October 1.
For now, however, the bill will have no effect on the NSA as it has not been debated by the Senate.
But the message from the lower house is clear.
It wants to embrace a court ruling and bar the National Security Agency from using personal electronic information from US citizens without a prior court order.
As it currently stands, under the so-called Prism program, the NSA focuses on foreign targets on the Internet via Facebook, Gmail and other services.
But the NSA has acknowledged it used information taken from the servers of such companies, without approval from a judge.
The Constitution and US laws require that the government obtain a court order before searching among data of US citizens.
Thursday's amendment would bar the NSA from carrying out any search without a court order, including information from Americans, even if their communications were picked up inadvertently.
The bill would bar the NSA and the CIA from including secret "back doors" allowing the NSA to skirt coded gateways and gain access to users' personal data. The NSA is accused of having done this for several years.
A year after the revelations made by former NSA contractor Edward Snowden, Congress is still debating how to reform US surveillance programs.