I received an interesting email recently. I use a computer at the BBC when working on Radio 4’s More or Less, and a BBC colleague got in touch to inform me that his computer was automatically downloading all my personal documents: tax returns; letters to my wife; photographs; the manuscript of a book I’m working on – everything. He hadn’t perpetrated some clever hack. His computer was being force-fed my files like a fattened goose.

A possible cause was Dropbox, a cloud computing service that copies designated folders on your computer and stores them remotely, so that you can access the files from anywhere. You can have copies of these folders on other computers, and if you save or change a file on one of them, all your computers will synchronise. It’s an utterly brilliant idea – provided that some computer somewhere doesn’t decide that not only does it need to keep your office computer in sync with your laptop, but it should also keep your colleagues in sync too.

I called Dropbox, and they protested that it was not their fault – apparently the files had somehow migrated across the BBC’s internal network, and my colleague’s Dropbox account was simply reacting to the fact that my files had arrived on his network drive. It transpires that my colleague had logged on to a computer where I had been sitting; it appears this act of hot-desking gave his Dropbox account access to my files.