As the Australian government looks to get its data-retention Bill through the Senate this week with the help of Labor, Communications Minister Malcolm Turnbull has told ABC radio that the vast majority of metadata queries made by police are to determine who owns a phone.
"Let's say somebody is killed, and they find on their phone a number of received calls from certain telephone numbers," Turnbull said. "They use this metadata access ability to go to the telco and say, 'Right, here are all these numbers. Who are the account holders of these numbers?' They give the police those names, and they can contact those people and say, 'What do you know about this? The person you called an hour before, is now dead'.
"So the vast majority of these checks are just designed to find out who actually owns a phone, who is using it."
Turnbull also rejected a Greens proposal to limit metadata access to investigations of serious crimes, and defended law-enforcement and intelligence authorities being able to determine which lawyers and doctors Australian residents visit.
"That information could be obtained if somebody stands outside the doctor's surgery and sees me walking in, they will know that," he said. "You've got to remember that this can only be accessed in the context of investigating a criminal offence, so this is not just for the police or anybody else to rummage around in.
"Let's say there was a concern that a doctor was breaking the law in some way, and his telephone records were looked at to see who he had been talking to, and they might come across your telephone number, well, then they would learn that you had spoken to that doctor.
"But so what? You're entitled to speak to doctors, we all are."
Last month, ASIO director-general Duncan Lewis told Senate Estimates that it needs telcos and service providers to retain metadata on all customers, even though upwards of 95 percent of it will be of no interest to authorities.
"95 percent, 99 percent, whatever the figure is, which will be of no particular relevance to the investigation," Lewis said.
After clearing the House of Representatives last week, the data-retention Bill is set to be debated in the Senate on Tuesday.
Liberal Democrats Senator David Leyonhjelm will join independent Senator Nick Xenophon and the Greens in seeking tougher privacy safeguards.
Senator Leyonhjelm wants to exempt lawyer-client discussions from scrutiny, and limit access to personal information by government agencies.
The Abbott government wants the laws through by the end of the week, claiming that they're crucial to thwart terror attacks and tackle organised crime. There are just three sitting days left before parliament goes on break before the Budget in May.
Prime Minister Tony Abbott said in February that metadata is "vitally important" in police work.
"Now, as we know, technology is changing all the time, and telecommunications companies are not keeping these records for as long as they did. We have, if you like, a burning platform, and as a result of that burning platform, increasingly, police and other crime-fighting agencies are going blind," Abbott said.
"That's why we need this metadata-retention legislation. It's an absolutely vital part of the national security legislation that this government has been progressively introducing over the last few months."