You're listening to a BBC Radio 4 podcast for a special series with the Oxford academic and

author on the subject, Timothy Garton Ash. In the final essay of five, he looks at the balance between free speech and privacy in a world where

we're sharing more of our lives online than ever before. Some years ago I had the strange experience of reading a file that the Stasi, the East German

Secret Police, had compiled on me when I lived in East Berlin.

It contained minute by minute accounts of where I'd been and who I'd met,

as well as photographs taken by a concealed camera.

These days we all have files full of far more detailed personal information.

What's more, we compile them ourselves? You probably carry around in your pocket a state-of-the-art surveillance device.

It's called a mobile phone.

Add to that all your emails, the complete history of your online searches and your Facebook

page, and you have a file beyond a Stasi general's wildest dreams.

Most of that data is held by mobile phone companies and the big internet platforms,

so some people now detect the face of Big Brother in Facebook and Google.

I once spoke at a speaker's corner type event about free speech at the Brandenburg Gate in Berlin.

Sponsored by Google.

Then someone piped up from the crowd

suggesting that the biggest threat to free speech is actually Google.

I don't think the Google PR man was best pleased.

As Edward Snowden revealed, phone companies and internet platforms have also shared vast amounts of data with American and British security agencies.

A basic characteristic of the Internet age is that it's become much easier to make things public

and more difficult to keep them private.

The ease of sharing things publicly is a huge gain for free speech. We can all be authors and publishers now.

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