Or law firms, potentially. When word got out that JK Rowling, author of that overrated series of children's books about sorcery, had written The Cuckoo's Calling (ostensibly by one Robert Galbraith) there was speculation that Rowling or her publicists were behind the leak. No, actually – it was her solicitor, who made the mistake of mentioning the real identity of 'Robert Galbraith' to his wife's best friend – who then tweeted it to the four winds.

The good news is that sales of the book went from a few hundred to a few hundred thousand virtually overnight – but not every solicitor will be so lucky. And Rowling has said that to call her disappointed at the revelation would be 'an understatement', in spite of the sales boost.