Legal professionals from the Electronic Frontier Foundation (EFF) and the US Department of Justice clashed in the courtroom over the warrantless wiretapping program instituted by the Bush administration.
The legal clash stems from a secret wiretapping program implemented by the Bush Administration in the wake of 09/11 and which the EFF has since vigorously opposed.
The court appearance stems from the EFF's attempts to stop the practice of recording communications involving US citizens without a federal warrant.
The EFF has argued that the warrantless wiretapping is illegal, but DoJ lawyers are retorting that the lawsuit should be thrown out of court as it could result in state secrets being disclosed.
The EFF contends that the wiretapping program - enshrined in law by Congress last September and which protects major telcos from lawsuits over the wiretaps - is illegal.
Infosecurity notes that the precise details of the government's warrantless wiretapping program have never been made public, although the EFF has contended it is widespread and acts as a dragnet surveillance of millions of ordinary Americans.
During his campaign against President Bush, Barack Obama had pledged that there would be "no more wiretapping of American citizens."
However, yesterday's courtroom clash appears to fly in the face of the campaign rhetoric.
John Yoo, meanwhile, who has previously penned a number of legal memos justifying the warrantless wiretapping program, has defended the measure in today's Wall Street Journal.
In his feature, Yoo said that the best way to find an al-Qaida operative is to look at all email, text and phone traffic between Afghanistan and Pakistan and the US.
"This might involve the filtering of innocent traffic, just as roadblocks and airport screenings do," he said.
Yoo's diatribe was responding to a report issued last week by a team of five federal inspectors general.
The report questioned the legal justifications for the wide-ranging surveillance program started in the wake of the 09/11 attacks.