Arrested, caged and DNA tested - for using MP3 player

An incredible story in London's Metro free newspaper. This story is almost unbelievable, a man listening to music on his mp3 player whilst waiting for a bus is reported to the police by a panicky passerby who mistakes his black mp3 player for a gun and reports this to the police. The police then monitor him on CCTV and follow him until he get off the bus when a firearms team surround him , arrest him and take him to the police station. This totally innocent man was fingerprinted and had a DNA sample taken which is now stored on the National DNA database, where it will remain forever. This poor man who had committed no crime or done anything wrong at all was treated like a criminal and his details will be forever on the police database linked to a possible handgun crime. If I were Darren Nixon I would be absolutely furious and looking for ways of suing the police for false imprisonment. I presume that if I take a dislike to anyone from now on, I should just call the police from a phone box and report that I have seen a stranger carrying what appears to be a gun and leave it all to the police; this cannot be right...