As warrantless electronic surveillance in the US surges, how far have civil liberties been eroded under the president?
On Monday, the US Supreme Court is hearing a challenge to the government’s controversial wiretapping programme, a policy that gives the government unprecedented power to intercept communications – and which has seen thousands of US citizens secretly monitored.
It has been brought by a group of attorneys, journalists and human rights organisations.
Following the 9/11 attacks, George W Bush, the then US president, secretly expanded the Foreign Intelligence Surveillance Act (FISA) to allow the government to eavesdrop on individuals without obtaining a warrant.
It became law in 2008 after getting the approval of the US Congress.
According to the American Civil Liberties Union, the programme has expanded under Barack Obama