If you want to be on TV, don’t go to Los Angeles or New York. Come to Chicago, where your wish is certain to be fulfilled. In fact, you couldn’t avoid it if you wanted to, thanks to the nation’s most extensive network of police surveillance cameras. Anytime you walk out your door, you may find an audience. This is one of Mayor Richard M. Daley’s proudest achievements, but the estimated 10,000 devices now in operation are not enough for him. He once expressed his intention to keep adding cameras until there is one “on every street corner in Chicago.”