The US Senate has voted by overwhelming majority to extend the provisions of the FISA Amendments Act of 2008 – the controversial law that grants intelligence agencies broad authority to spy on US citizens – for another five years.

The law, which was first passed in the wake of the Bush-era warrantless wiretapping scandal, grants telecoms companies blanket immunity from prosecution for participating in domestic surveillance.

In addition, it specifically authorizes intelligence agencies to monitor the phone, email, and other communications of US citizens for up to a week without obtaining a warrant, provided one of the parties to the communications is outside the US.

Critics of the act claim it violates Fourth Amendment protections against unreasonable search and seizure, but the Obama administration has argued that the law "is necessary to keep the American people safe."

"Intelligence collection under [the act] has produced and continues to produce significant information that is vital to defend the Nation against international terrorism and other threats," the administration said in a policy statement in September.

As originally drafted, the law would have expired on Monday, but on Friday the Senate elected to extend it through 2017 by a vote of 73–23, with four abstentions.

Several proposed amendments to the bill would have offered increased transparency and added privacy protections, but all were rejected in the Senate vote.

Civil rights organizations were quick to blast the vote, characterizing the FISA Amendments Act as an unconstitutional law that grants the government excessive and unchecked surveillance authority.

In a statement, the Electronic Frontier Foundation called the vote "shameful" and "disgraceful," adding, "Make no mistake: this vote was nothing less than abdication by Congress of its role as watchdog over Executive power, and a failure of its independent obligation to protect the Bill of Rights."

The American Civil Liberties Union also chimed in, saying, "It's a tragic irony that FISA, once passed to protect Americans from warrantless government surveillance, has mutated into its polar opposite due to the FISA Amendments Act. The Bush administration's program of warrantless wiretapping, once considered a radical threat to the Fourth Amendment, has become institutionalized for another five years."

Despite such objections, however, the extension is now all but a done deal. The House passed it in September by a similarly wide margin of 301–118, leaving it only for President Obama to sign it into law, which he is expected to do over the weekend. ®