We all love the dark knight trilogy. Following a rejected Batman origin story reboot Joss Whedon pitched in December 2002, Warner Bros. hired Christopher Nolan and David S. Goyer to script Batman Begin. The duo aimed for a darker and more realistic tone, with humanity and realism being the basis of the film.
After his parents die, Bruce goes to Princeton University. When Bruce becomes a young man, he returns home to Gotham City from Princeton University, intent on killing Joe Chill, whose prison sentence is being suspended in exchange for testifying against the mob boss Carmine Falcone. Falcone says to Bruce, "You're Bruce Wayne, the Prince of Gotham--you'd have to go a thousand miles to find someone who doesn't know your name!” Realizing that Falcone is right, and that he cannot truly understand what he intends to fight as a wealthy playboy, he abandons his life at home, stowing away on a cargo ship and travelling the world for nearly seven years.
In the beginning of the movie ‘Batman Begins’, Ra's al Ghul visits a person in the prison and they have a little conversation, in which Ra's al Ghul identifies the person as Bruce Wayne. Whereupon, the person asks, “How do you know my name?” to which he replies, “The world is too small for someone like Bruce Wayne to disappear...” That means people are aware of Mr. Wayne’s absence in Gotham.
20 years after Bruce's parents' death, Bruce Wayne returns to a Gotham City that is mostly ruled by Falcone. He is been gone for 20 years and he suddenly appears in his office. Following which it’s all on the news of Bruce’s return to Gotham. Everybody knows the prince of Gotham has returned.
Afterwards Bruce visits applied science division of Wayne enterprises. He borrows some techs from the applied science division. And assembles that tech to create his bat suit. William Earle is aware of Bruce visiting the applied science division.
Bruce Wayne is the richest person in Gotham, just few days after Bruce’s return to the Gotham; Batman appears and starts fighting crimes. He uses tumbler as his vehicle, looking at the tumbler anybody can make out that it is worth millions. Batsuit also looks quiet costly and all the gadgets he uses are also worth a lot of money. In dark knight , batman uses Batpod which is also worth millions as it is equipped with hi-tech materials. In dark knight rises batman uses the Bat , a super hi-tech flying vehicle. And in the end of the movie, bane uses a lot of tumblers.
Coleman Reese, an accountant at Wayne Enterprises, deduces Batman's true identity and plans to reveal it. So, an idiot can identify batman as Bruce Wayne. John Blake , a rookie police officer recognizes batman as Bruce Wayne but commissioner James Gordon who meets batman a lot of times and also uses his tech for fighting crime cannot recognize him.
my point here is, anyone in Gotham can make out that only Bruce wayne has the power and money to use all this hi-tech stuff.