Who's making money out of your data?

Citizens everywhere should be aware of the trails of data they leave around them every day. Many of us may give it little thought but to the data giants it's gold dust.

The tech companies have an intellectually plausible - even reasonable, they would argue - defence. In return for free services, they build profiles of you which advertisers can use. They are more transparent than they have historically been: you can read their terms and conditions if you like.

But Ravi Naik, a data lawyer who worked on the Cambridge Analytica case, believes that citizens and consumers are not really providing fully informed consent when they use apps and online services.