Makers of baby milk must be doing very nicely out of the rules on carrying liquids in hand luggage. My daughter, flying to Spain yesterday with her 10-month-old son, turned up at the airport with half a dozen cartons of milk. Security staff asked her to open one and taste it to prove it wasn’t bomb-making liquid. She did, and poured it into a bottle. Then she was told she would have to open and taste all the other cartons or leave them behind. Had she opened them, of course, the milk wouldn’t have kept, so she had to leave them — and buy another batch of cartons when she got airside.