When Nandan Nilekani began working on providing a unique identification number to half of India’s billion-plus people four years ago, he ran into a wall of problems.The main criticism was that 120bn rupees(£1.72bn; $1.89bn) project was also the world’s biggest biometric exercise.Not surprisingly Mr Nilekani, info-tech whizz turned head of the country’s Unique Identification Authority of India, faced tough questions over access and misuse of personal information, surveillance, profiling, securing of confidential information by the government and threats of budget cuts. A parliamentary panel even trashed the idea, saying it …