Why Rudolph Giuliani's "zero tolerance" approach to crime worked. "New York's recovery certainly started with a clampdown on anti-social behaviour�graffiti writing, street drinking, turnstile jumping, and so on. But these low-level miscreants were then shackled, fingerprinted, and (if they didn't have identification) often held overnight in police cells. Over time, the police built up a store of information that they used to solve all sorts of crimes. British police, with their milder approach and heavier form-filling burden, will find these methods hard to copy. Secondly, New York's cops were trying out more aggressive methods such as undercover buy-and-bust operations, neighbourhood sweeps and �vertical patrols�, in which entire tower blocks were raided. These did more to take bad guys off the streets than harassing squeegee men. This style of policing only works if citizens are willing to trade liberty for security."