Pretty much all the hacking techniques in the Girl With The Dragon Tattoo are real and used regularly by not only the bad guys, but also law enforcement, penetration testing teams, and security auditors.
Sure, Hollywood dramatises them, but in this case, not by much. I have managed teams of individuals who can do the things shown in this film, and in my dim and distant past, I did some of them myself.
Have a look at this question on Password Strength for some useful information on password strength, and why humans are so bad at making strong ones.
Regarding video feeds from CCTV cameras, there are now a few companies with systems that pull information from multiple frames to interpolate/extrapolate high quality stills. But no, you can't turn the view round to face the opposite direction the camera was facing (Enemy of the State). And you can't zoom in and pan indefinitely (Blade Runner)
A really good example of real techniques used today by attack groups is given by the Mr Robot series. If we exclude the psychotic/hallucinogenic plot themes, all the hacking, intrusion and exploitation carried out by the hackers are real.