About seven months ago I was woken in the night by a kerfuffle outside my window. We get a lot of nocturnal kerfuffles in Hackney - broken-down drunks bellowing mournful songs to the heavens, or gaggles of squealing fashion students toppling into the bins - but this one sounded different. An argument between two men, muted but urgent. I got out of bed and peered through a crack in the curtains, making sure to keep myself out of sight. I am not one of nature's have-a-go heroes.