Thanks VK. In fact they made a note of all the people I had visited and took copies of the visit cards. It was very intrusive and because of the actions of a few we all seem to be made guilty until we can prove our innocence.
Just how many foreign travelers to the UK, with perhaps limited English, get caught by this. Is this a revenue raising scheme as most people think it more time consuming and costly to take on a lawyer, return to the UK to fight the order etc. It would be nice to find out.