Every day, anyone who is connected to the internet leaves an ever bigger trail of data behind them. But how aware are we of who is collecting this information and of who benefits from it? I spent a day without data to to explore these questions.
My guide for this no-data diet is Dr George Danezis, an expert on privacy and information security at University College, London. As I sit at the breakfast table, handing over my gadgets he sets out the challenge I face:
"Your job today is going to be very difficult, You won't be able to use the internet, but you also won't be able to do lots of other things - in fact you won't be able to live a 21st Century life."
As someone who is addicted to being online, checking Twitter the moment I wake up, still reading online news last thing at night, giving up my smartphone is hard.
But George also makes me hand over my travel card and my BBC identity card which gets me into my office. Both record data about my location, so they have to go.
George explains that there are three big collectors of data: companies, governments and the police and the security services. Consumers may have grown accustomed to this data collection and in some cases see benefits.
But we may still be in the dark about some aspects. "It's collected for primary but also secondary purposes, you might be handing over data while you're shopping and that might be used later for marketing or working out health insurance."