Illustration by John Sadler www.johnsadlerillustration.com 

• CASUALLY mentioned in your story about plans to zone Hampstead Heath for professional dog walkers is a paragraph about the City of London using technology similar to that used to track Premiership footballers’ performances to find out what dog walkers get up to, (Leash lease: Heath dog walkers will be given a zone, News, October 7).

We have become so used to being under surveillance that we don’t seem to bat an eyelid at this sort of thing any more. But surely it prompts the question: What else are they watching us do on the Heath? Or anywhere else come to that?

Oh, and where do you think you’re going?

C BROWN, NW5