Three quarters of Facebook users unaware of how much it knows about them

Most Facebook users don't realise how much Facebook knows about them and are uncomfortable with it when they find out, research suggests. A study by the Pew Research Centre in Washington DC found that 74 per cent of American users did not know about a key privacy page which shows them how Facebook has categorised them based on their data. When shown this information, 51 per cent of those surveyed said they were "not very comfortable" or "not comfortable at all" with its existence. The research c