The NSA should have unlimited ability to access digital data when it comes to matters relating to terrorism and other national security threats, a federal judge has said.

Speaking at a conference about privacy and cybercrime in Washington, D.C, Judge Richard Posner of the US Court of Appeals for the Seventh Circuit said that Congress should limit the federal agency's use of the data it collects, but there shouldn't be a limit on what information it collects.

"Much of what passes for the name of privacy is really just trying to conceal the disreputable parts of your conduct," Posner said. "Privacy is mainly about trying to improve your social and business opportunities by concealing the sorts of bad activities that would cause other people not to want to deal with you."

He was not only critical of mobile OS companies for enabling end-to-end encryption in their software, but also questioned the need of legal protections for smartphone users, saying he fails to understand what information on smartphones should be shielded from the government.

"If someone drained my cell phone, they would find a picture of my cat, some phone numbers, some email addresses, some email text," he said. "Other people must have really exciting stuff. Do they narrate their adulteries, or something like that?"

Other speakers at the event, including deputy solicitor general in the US Department of Justice Michael Dreeben and Judge Margaret McKeown of the US Court of Appeals for the Ninth Circuit disagreed with Posner, with the former relating privacy to freedom and personal autonomy and the latter advocating legal limits on government surveillance.

Posner comments came on the day when it was revealed that the NSA spied on more than 1,200 e-mail accounts associated with major wireless network operators as part of the agency's efforts to collect information from around the world in the name of national security.