Hackers

Scenes in the movie, and in Razor and Blades show, depict using a cassette recorder to play tones into a phone to make free calls. Coins dropped into pay phones used to trigger specific sounds that actually could be duplicated and used to fool pay phones into thinking you had paid for a call. This was also accomplished using a device called a tone generator. Also known as a Red Box.

In the early establishing shot of Dade (Jonny Lee Miller) and his mom (Alberta Watson)'s New York apartment, (he's in a robe, she's on a couch), sun's clearly (and brightly) streaming in through the window, yet, when he leaves the apartment, he's seen exiting the brownstone from a basement apartment. The likelihood of light streaming in with no shadows - anywhere in NYC (much less a basement apartment) is pretty low.