A US law allowing the collection of all Americans' phone records looks set to expire at midnight.
The US Senate is holding an emergency session today to debate the controversial issue.
Senators are split on whether to renew the provision in the Patriot Act which allows all phone calls to be tracked by the intelligence services.
The White House has warned that letting the powers expire would put Americans at risk.
In 2011, President Obama signed a four-year extension to key provisions of the Patriot Act, including sanctions for metadata collection, wiretapping and surveillance on terror suspects that are not affiliated with any group.
Marcy Wheeler is an independent journalist in Washington DC. She spoke with Newstalk's Shona Murray about what will happen if the provisions expire:
You can listen back to the full World in Motion interview with Marcy Wheeler below:
