The Big Apple is turning into Big Brother, civil liberties groups have warned in response to a new plan from New York city's police chiefs to photograph every vehicle entering Manhattan and hold the details on a massive database. As well as placing cameras at all tunnels and bridges into Manhattan, the 36-page plan, called Operation Sentinel, calls for a security ring to be erected at Ground Zero and for a 50-mile buffer zone around the city within which mobile units would search for nuclear or dirty" bombs. [The] 3,000 cameras that could be mounted as a result of the plans of the New York police ... have provoked outrage in the United States. Donna Lieberman, director of the New York Civil Liberties Union, said the idea of tracking the movements of millions of people was "an assault on the country's historical respect for the right to privacy and the freedom to be left alone". The NYCLU is pressing the New York police to release further details of its intentions under freedom of information laws. The toughest element of the scheme relates to preparations to secure Ground Zero once the six-hectare site is rebuilt and open to the public again. Those measures include moveable roadblocks, security cameras across lower Manhattan and an underground bomb-screening centre through which all delivery vehicles would have to pass. The plan to video the number plates of every vehicle would be applied to all points of entry into Manhattan, including the main Brooklyn-Battery, Holland, Lincoln and Midtown tunnels and Brooklyn, Manhattan and other bridges.