From Rosemary Campbell
I tried to spot the animals hidden in the picture accompanying your article on a new technology used to camouflage images, but I was foiled (17 July, p 17). If this technique is indeed going to be used online to make Captcha images to distinguish real people from software bots, then a lot of people are going to end up even more frustrated by computer systems than they already are.
Glen Waverley, Victoria, Australia
