The Dark Knight was released in the summer of 2008. This was almost 7 years after 9/11.
Many aspects of that film were deliberately done to explore post 9/11 America. This includes the methods Harvey Dent uses, the things the Joker says, and the surveillance scenes and more.
These discussions surrounding surveillance have been around long before 2008.
Of course. The use of mass surveillance in the movie is not-so-subtly referencing the PATRIOT Act. But again, it's presented as a moral dilemma, and multiple protagonists acknowledge that it's far too powerful to exist, and its use is a last resort. It falls into the larger theme of Joker pushing Batman to violate his ethics for the greater good.
One could argue that because it was successfully used to catch Joker, the movie concludes that mass surveillance is sometimes necessary to stop evil, but it's at least presented as a dilemma. A massive corporation coming out and saying "mass surveillance is awesome because you can find lost pets" is a crazy escalation of the surveillance state.