The creator of the world wide web has hit out at US and UK spy agencies, condemning their online encryption cracking as "appalling and foolish".
Sir Tim Berners-Lee argued cracking online encryption, which protects millions of users' data, would weaken online security and benefit criminal gangs and hostile states.
The computer scientist said the checks and balances implemented to oversee the agencies had failed, and accused the security agencies of weakening online security.
Sir Tim, who founded the web on Christmas Day 1990, argued publishing leaks by NSA whistleblower Edward Snowden was in the public interest as it "uncovered many important issues" and called for a "full and frank public debate" about the scale and scope of state surveillance.
He said whistleblowing and responsible reporting can "step in" to protect society's interests.
"Whistleblowers, and responsible media outlets that work with them, play an important role", he told The Guardian.
"We need powerful agencies to combat criminal activity online - but any powerful agency needs checks and balances, and based on recent revelations it seems the current system of checks and balances has failed."
His comments come as intelligence chiefs from MI5, MI6 and GCHQ prepare to face MPs later this afternoon in Westminister for a grilling on their practices and conduct from Parliament's Intelligence and Security Committee, led by Sir Malcolm Rifkind.
The 90-minute session is scheduled to begin at 2pm GMT and will be broadcast with a time delay to allow the removal of anything that could threaten national security or safety of those employed by the agencies.
Sir Malcolm told Sky's Murnaghan Show that the committee would not ask questions that would force intelligence chiefs into revealing secret information.
He said: “We do ask them that in private but, what has become already evident, is you can have an intelligent and mature debate on intelligence issues, including the intelligence chiefs themselves, without having to reveal specific secrets.”
The hearing will be the first time intelligence bosses are quizzed in public by a committee.