Sunnyvale, Calif. — WHEN Jane Landenberger of Bedford, N.Y., got a call from the telephone company recently she may have unwittingly had a close encounter with the ''network revolution.''
She learned that her telephone credit card had been billed for 2,578 pages of calls - $109,504.86 worth - to and from points spanning the United States, Europe, Africa, and the Far East.
It is likely that Mrs. Landenberger's credit-card number was posted on several electronic bulletin boards. These are computer systems hooked to telephone lines which give computer cognoscenti a way to exchange information and gossip. There are currently between 4,000 and 7,000 such systems operating in the United States.
These computer message centers are used in a number of ways. John James, author of a software program that allows Apple II computers to serve in this capacity, operates his own bulletin board in Santa Cruz, Calif. ''Right now there are 78 different discussions on my system. There's something of interest to almost everyone,'' he says. Topics include religion, philosophy, neighborhood power, science fiction, and foreign policy, as well as a number of computer matters.
Compared with chatting over the back fence, computer networking has one major drawback: Telephone bills tend to mount quickly. This problem is particularly acute for the computer hackers who try to break into other people's computer systems. These have taken to routing their calls through several long-distance services to cover their tracks. The less scrupulous people involved in networking spread around known telephone credit-card numbers as well as instructions for breaking into various computers by posting them on electronic bulletin boards.
But such highly publicized abuses as the ones seen in Mrs. Landenberger's phone bill represent only a small part of what is going on. Many here in Silicon Valley believe that computer networking is a new form of communication that will radically, and beneficially, affect society.
This view was clearly evident in a small gathering that took place one night last month (March). Under auspices of the Computer Literacy Book Shop, a few dozen people gathered in a large nearly empty auditorium to discuss the various issues surrounding networking.
An illustration of the potential of this new form of communication was provided by Lee Felsenstein, designer of the Osborne computer. He is involved in an effort called the Community Memory Project, based on an experiment that Mr. Felsenstein and his compatriots ran a number of years ago.
They placed several computer terminals in public areas around the city of Berkeley, Calif., making them available for general use. They expected most public use of the system would involve exchanges of information about jobs, homes, and cars. Instead, music turned out to be a major topic of discussion. Poets entered lines of doggerel and their phone numbers to advertise their skills at contract versifying; others experimented with typewriter art; and a number of people exchanged information on where to find the best bagels.
''We saw that we had a new type of information utility which looked like it could provide a channel to help people change what they are doing to something closer to what they think they want to do,'' Felsenstein remarked.
Unfortunately, their experiment needed more work technologically. So they have spent the intervening years developing the hardware and software necessary to make such a community computer system practical. Now they are ready to reestablish this system on a permanent basis.
What Felsenstein and his friends are starting is a network of coin-operated computers located in public places. Each terminal will be owned by an individual or group. They will be networked together and will follow a ''constitution'' not yet finalized. All information in the network will be public. There will be no prior review of the information available to others on the system. But there will be the capability for users to make comments on information placed in the system.
Ultimately, members envision community systems tied into regional networks corresponding to telephone area codes, which, in turn, would be interlinked by satellites.
''It's admittedly a grandiose scheme. That's what makes it worth doing,'' Felsenstein says, half jokingly.