While some deliberately open up internet connections to the public, there are many individuals and companies that unwittingly provide access to all and sundry

Perhaps you thought that big business had completely taken over the internet but now there is a movement to give it back to the community as groups of activists in Silicon Valley set up free high-speed internet connectivity services.

"It's the new techno-socialism," says Mr Seamus McAteer, principal with San Francisco-based consulting firm The Zelos Group.

"It's the ham-radio geek turned hacker to give the community free internet access."

The service provides people with internet connections up to 30 times faster than a normal modem and is available to anybody who cares to install a wireless adapter card on their computer.

There's only one snag: you have to be in range of a wireless network to be able to receive the service.

In San Francisco, an organisation called the Bay Area Wireless Users Group (BAWUG) is providing coverage in most areas of the city by making their home wireless networks available to the public. Some members are even attaching large antennas to their roof to broadcast the signal further a field.

All the user has to do is go to the organisation's website at www.bawug.org and download the map to find out where the service is available. So in some parts of the city people can get free web access from a coffee shop, a shopping mall or even a park bench.

One day last week I was sitting in a friend's house in San Francisco when I happened to mention that I was interested in this community group.

A phone call was made and 20 minutes later I was driving through San Francisco's funky Mission district in an open-top car with Thomas Hardman, a computer engineer and a member of the group.

On his lap was his portable computer, which was equipped with a wireless networking card. As we drove through the district, little red dots appeared showing the access points. We then settled in Thomas's local café and browsed the internet. Marvellous!

The service is based on a home and office networking standard called IEEE 802.11 (terrible name). The technology dispenses with the need to use a cable to connect to a home or office network.

Several years ago it was expensive and difficult to install. Now, however, wireless network equipment costs less than $100 for the router and $50 for the network card.

Furthermore, companies such as Apple are shipping every computer with wireless networking capabilities built in.

Many people are installing wireless networks in their homes either because they want to browse the Web from the loo or because they want to share a DSL or cable modem line with their neighbours. The equipment does, in fact, have a range of up to 500 feet.

Couple this with the growing number of DSL or cable modem subscribers in the city and you get widespread high-speed internet access.

But there is a dark side to the technology. While BAWUG members deliberately open up their internet connections to the public, there are hundreds of individuals and companies who have bought wireless networking equipment and unwittingly provide access to all and sundry.

High in the hills above the city of Berkeley in Oakland, just across the bay from San Francisco, Peter Shipley sits in his black sedan armed with an antenna, a GPS receiver and a laptop computer.

From there his powerful antenna can tap into hundreds of corporate networks.

"It is very disturbing how many financial, legal and corporate networks are wide open with no protection at all," he said.

Mr Shipley has made a map naming the networks he can easily access. He believes that there are thousands of unsecured home and corporate networks.

Many corporate networks not only enable people to log on and get access to the internet but also provide access to their internal networks.

Mr Shipley works as a security consultant and has made a business out of detecting weaknesses in such wireless systems.

"People are just broadcasting their most sensitive data to anybody who cares to listen."

Using software called NetStumbler, a wireless network card and a laptop computer, it is easy to detect open networks. To get around this there is software available that will only allow computers with a designated user name and password to access the network.

However, there also is hacker software called AirSnort, which will intercept these passwords in the air, break the code and break into secured networks.

So corporations who want to make sure that they do not pass out corporate data have to encrypt all sensitive data passing over the air.

Scary, eh. Still, as always, new technologies bring many advantage and many problems too.

On a more personal note this will be my last column from Silicon Valley for some time. I am moving to Japan and will hopefully bring you as many strange tales from there as I have from Silicon Valley. I can still be reached at www.niall.org.