The European Union’s data watchdog has compared Google and Facebook to “digital sweat factories” where nobody is allowed to clock out.

European Data Protection Supervisor Giovanni Buttarelli made the criticism in reference to the way internet companies depend on constantly farming people’s personal data.

Mr Buttarelli said: “The digital information ecosystem farms people for their attention, ideas and data in exchange for so called ‘free’ services. Unlike their analogue equivalents, these sweatshops of the connected world extract more than one’s labour, and while clocking into the online factory is effortless it is often impossible to clock off.”