Walter F. Parkes and Lawrence Lasker co-wrote WarGames in 1984 - it was the first film to deal with the subject of hacking and a success at the box office, but to anyone in the computer industry it was technically absurd. Eight years later, they have returned to write and produce Sneakers. It also deals with hacking and with Robert Redford, Sidney Poitier and Dan Akroyd playing central roles it looks set to become a box office success as well. Unfortunately, to anyone with more than a cursory familiarity with computing, the film is still as full of holes as Gruyere.

Of course, under normal circumstances, you wouldn't expect a Hollywood film to reflect the complexities of technology on-screen, but this seemed to be no ordinary film. Several months before it was screened, its promoters had taken a booth at the PC Expo computer trade show to raise awareness. The director and other staff opened a Sneakers conference on CompuServe, a computer-based global information service, and answered questions about the film. Even the publicity for the press was a little unusual - it came in floppy disk form as well as on paper. "Captain Crunch", a legendary hacker of the 1970s who learned how to make free telephone calls using tones generated by a whistle from a cereal box, was apparently one of the sources consulted (though his name is not in the credits). 'Clandestine meetings with underground hackers, FBI men, cryptologists, wiretappers, professional perpetrators, and an endless stream of cyberpunks' are also mentioned in their publicity material.

Why, then, is the computing element of the film simplified to the point of absurdity? Partly because computers are boring to watch. Even the act of connecting legitimately to a remote computer takes at least thirty seconds - too long a time to keep the viewer's attention in a Hollywood film. Little wonder, then, that network connections in this film are made instantly, with just a few keystrokes - I wish the systems I dial into would work that fast!

The art of hacking, while fascinating to its participants, is a very poor spectator sport. It normally involves hours of painstaking research, dialling number after number, consulting technical documents and trying different commonly-used passwords. The device around which the plot turns is a black box which can almost instantly decode any encryption scheme, opening the door to any computer in the West. When Redford and his gang of misfits get ahold of this implausible McGuffin, they test it by connecting in a few seconds to the US Federal Reserve, the national power grid and air traffic control (no passwords or other identification seem to be required). The fundamental weakness to this little demonstration is that these and other sites are almost certainly protected by the best kind of security of all - the physical isolation of all means of access. Why would an airport have a phone line attached to its computers? So that air traffic controllers could work from home?

But this is just carping - the reason that the technical side of the film is flawed is that the whole film doesn't take itself at all seriously. The badges passed out at the computer exposition read, "Sneakers - we'd tell you about it, but then we'd have to kill you." This suggested a rather dark and serious conspiracy film like The Conversation or The Parallax View. What eventually emerged is a much more light-hearted buddy film. When the National Security Agency wants possession of the magic box at the end, it isn't willing to kill to get it - instead it offers our heroes whatever they want - a Winnebago camper van, a holiday in Europe and Tahiti and even a female agent's telephone number for the geekiest gang member.

Attacking the accuracy of this film is like taking a hammer to a souffle. The fact is, computer users in the US who have seen the film seem to have liked it a lot. As with most action adventure pictures, they are quite happy to suspend disbelief and enjoy.