Facebook co-founder Mark Zuckerberg has hit out at the US government over claims it covertly used the social networking site to gather intelligence data on individuals.
Zuckerberg said he was "confused and frustrated" by the reports and stressed that to "keep the internet strong, we need to keep it secure".
He wrote in a Facebook post: "When our engineers work tirelessly to improve security, we imagine we're protecting you against criminals, not our own government.
"The US government should be the champion for the internet, not a threat. They need to be much more transparent about what they're doing, or otherwise people will believe the worst."
The internet mogul said he called President Barack Obama to discuss the issue, adding, "Unfortunately, it seems like it will take a very long time for true full reform."