Sir Tim's web worries

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Media captionRory Cellan-Jones spotted by Sir Tim Berners-Lee filming with Google Glass

The creator of the world wide web is talking about the dangers of mass surveillance, then he pauses, looks at the front row and points out that someone - OK it's me - is filming him with Google Glass.

Sir Tim Berners-Lee laughs and moves on to talk about the need for a system of checks and balances to ensure governments are at least cautious about spying on their citizens.

He is speaking at an event called The Web We Want at London's South Bank Centre, which brings together artists, various web luminaries and students from local schools to look into the future as Sir Tim's creation celebrates its 25th anniversary. And what we get from the man himself is a list of threats to the web's state of health.

A web secure from government spying is just one worry - he repeats his disquiet about the GCHQ's role as what he calls "the handmaiden" of the National Security Agency, carrying out mass surveillance under much less supervision than the American agency.

Sir Tim wants to reinforce the idea that judges should have to approve any surveillance of an individual, and says the intelligence agencies should have to provide details later of just what their methods have achieved.

He seems less concerned - despite my Google Glass activity - with the way companies and individuals are watching our every move. But here his focus is on net neutrality - the principle that all web traffic is treated equally - which he sees as being under threat: "There's this huge corporate pushback trying to eat away at these core principles," he warns, calling for this year to be when the public is awakened to the importance of this idea.

He is irritated too about what he sees as corporate roadblocks to getting onto the open web. He describes a recent experience where he had to jump through hoops set up by BT - "do you want to set up parental controls? No. Do you want BT's added features? No." before finally getting onto the web, only to be greeted with a BT advert. "If you want me to look at an advert, I will charge an administration fee," he says, to chuckles from the audience.

From the audience, the founder of Mumsnet Justine Roberts issues a stirring defence of anonymity as the guarantor of free expression online - "being anonymous doesn't mean you're a troll" she insists. Sir Tim agrees that anonymity is often an essential prerequisite for individuals wanting to share their views safely.

The mood of this event is clear - what people want is a free, open web, where governments and giant corporations do not have unlimited power to control, examine and direct the traffic, and where individuals can express their politics and their creativity without fear. Of course some of those principles are in conflict - freedom for one person to express themselves anonymously can turn into freedom for others to be bullied into silence. And governments will argue that without the power to keep an eye on what is happening online, there is a risk that groups which aim to destroy our liberties will prosper.

And what remains unclear is how Sir Tim or anyone else can make sure their vision of an open web is realised. The very fact that the governance of the web and the wider internet is so freeform - and is currently in danger of fracturing - means it is hard for anyone to pull the levers. Sir Tim can act as the moral conscience of the web, but why will governments or giant corporations feel obliged to listen to him?

Still, it is always inspiring to hear from the man who has never sought to profit from his creation. One schoolboy in the audience asks him what inspired him to create the web - "I was just frustrated it didn't exist," he replies.