A furore has broken out after a whistle-blower revealed last month that the National Security Agency (NSA) in the US has had direct access to citizens' emails and social networking content.
Under the Prism programme, officials are able to retrieve data held by some of the world's biggest internet companies, including Google, Facebook, Microsoft and Skype. The surveillance has been part of the US's battle against terrorism since 2007.
But the source of the leak - Edward Snowden, a former technical assistant at the Central Intelligence Agency who fled to Hong Kong, then Russia, and is now seeking asylum in a number of countries - believes that "what they're doing (poses) a threat to democracy".
Snowden's actions have divided opinion, with some journalists claiming that he deserves a medal for exposing a danger to our freedom. Journalist Glenn Greenwald of The Guardian, who broke the story, wrote that from a civil liberties standpoint, the collection of phone records - also revealed by Snowden - was "rampant abuse and it needs sunlight. That's why this person came forward and that's why we published our stories."
But others, such as John Boehner, speaker of the US House of Representatives, take a different view of Snowden's actions. Boehner told ABC News: "He's a traitor. The disclosure of this information puts Americans at risk. It shows our adversaries what our capabilities are. And it's a giant violation of the law."
Collecting personal data and information is, arguably, vital to intelligence gathering and counter-terrorism strategies.
Charges against Snowden have already been filed by the US Department of Justice, and the Federal Bureau of Investigation and the NSA have launched investigations. "If Edward Snowden did leak the NSA data, as he claims, the US government must prosecute him ... and begin extradition proceedings," said Peter King, chair of the House of Representatives Subcommittee on Counterterrorism and Intelligence.
US president Barack Obama has said that surveillance programmes are being run in a way that balances privacy and freedom: "If we did everything necessary for our security, we would sacrifice too much privacy and civil liberties, but if we did everything necessary to have 100 per cent privacy and civil liberties protections, we wouldn't be taking common-sense steps to protect the American people."
What do your students think? Use this story to start a debate, or as the basis of an essay-writing exercise, which could cover the history of surveillance and civil liberties.
- Debate this motion: "Blowing the whistle on practices that appear to invade privacy is always a good thing."
- Should whistle-blowers like Snowden face charges of treason? On what grounds do students agree or disagree?