Sam and Lucy are meeting for a late breakfast at the Wolseley. This is no ordinary brunch, but Eggs Benedict to celebrate their free-range days: the end of school, the dreamy lull before the A-level results. Right now, the world is their oyster. Tomorrow morning, Lucy leaves for a week in Corfu and Sam’s off for five days fishing on the Spey. But today, it’s the freedom of the city: the Royal Academy Summer Show, Hatchards, a movie. As they leave the restaurant, they stop to collect Lucy’s case, all packed for her trip to Greece. There’s some confusion. Waiters scurry around. Chefs peer out. The case is gone. The manager looks worried. They go to the office upstairs and rewind the CCTV. Together, they watch a man walk out of the restaurant with the case within seconds of Lucy handing it over. The police, when they finally arrive, barely glance at the footage. One murmurs to his partner: ‘We’re not talking bombs here we’re talking bikinis and flip-flops.’

A smart restaurant near Sloane Square. Four friends greet each other. They look like Ladies Who Lunch. They aren’t. They have fitted this into their work lives to celebrate the birthday of A. who has just finished a long regime of chemotherapy. Her wig is called Amélie. They toast to ‘Life with a capital L’ with house Champagne by the glass. When B. gets up to pay, she discovers her bag is missing. Inside the bag: diary, credit cards, address book, mobile, sunglasses, car keys. She doesn’t usually drive here from Fulham, but today, she dropped eight bags of her father’s clothes off at the Red Cross shop on Old Church Street on the way. Her car keys have the magic button that unlocks the car from a block away. This is not an urban legend: her car is gone, too. The police drive her home in case the thieves are in her house, but they’ve come and gone, quietly helping themselves to a laptop, small flatscreen television, clocks and jewellery while B.’s newly widowed mother sat in the garden listening to The Archers.

These aren’t Bond Street heists of diamonds worth zillions. These are tales of everyday folk. And what’s the monetary value of the journal Lucy has written all year? Of a laptop with a gap-year of emails from a daughter in Peru? ‘Change your locks this afternoon and get in touch with the insurance,’ the police advise B. New locks cost £486, but don’t buy peace of mind when you know that someone has cased the joint and just made off with the most portable stuff. In the country, we turn on our burglar alarms at night, following a spate of burglaries when the house was full of sleeping people and the dogs safely shut up in the kitchen. We figured it was our isolation that appealed to burglars, that city dwellers were less vulnerable. But rural and urban police alike admit that they can’t really do anything about the rise in crime. They are fully stretched trying to find terrorists, and anyhow the prisons are full. The ordinary burglar doesn’t feel that he’s in great personal peril if he pops into a restaurant for a briefcase or a handbag.

Once your bag is gone, you never again put anything on the floor. You carry one credit card only, memorise your PIN and keep your keys away from your identification. And ‘remote’ car keys? ‘They’ve made car theft a doddle,’ says our man from Sun Alliance. I do love that little ping and flash of lights, but it’s probably better to let go of that little illusion of power, along with the illusion that we’ve dealt with crime, and the causes of crime.