I don’t know that it would necessarily translate well to film, but The Cuckoo’s Egg is a good real-life story involving hackers, the NSA, CIA, FBI, the KGB and one long-haired Berkeely astronomer in the middle of it all.
A high school kid is really into computers right at the dawn of the internet explosion (you even have a shot of him actually putting the phone receiver onto his modem to connect).
THe thing is he loves to play games. Somewhere out there he finds a server that has a lot of really enticing games on it but is highly secure. So he researches the guy that made the software in order to look for a backdoor way to get in.
What he doesn’t know is that this computer system is actually the same one that NORAD uses for national defense so when he plays “Global Thermonuclear War” against the computer it looks to everyone in NORAD that a the russians have really launched their nukes at us.
And the fun ensues.
[Sandra Bullock] “My whole life’s on the compeeuooooooter!” [/SB]
A documentary about the creation of it. 
New rule: Documentaries don’t count.
Actually, as JCorre suggests, a modern remake of War Games would probably be pretty cool, if the computer use was realistic.
How about if we have 2 main characters, one female, one male.
She owns a small bookstore and he runs a big franchise book-store.
They hate each other, but without knowing it they have an on-line romance through their Email.
I think a Meg Ryan and a Tom Hanks would be perfect for the parts.
Now we need to find a good screenwriter.
Somebody suggested Nora Ephram(?) to me, but I don’t think she could get away with a story like this.
No, let’s use some digital inserting trechnology to have Jimmy Stewart be the lead.