Open wireless Internet (Wi-Fi) hubs like coffee shops and local area networks are becoming the norm in Ballard, making connecting to the Internet quick, convenient and most of the time free, for the casual Web browser and the on-the-go businessperson.

They can be seen in coffee shops around the neighborhood, busily hunched over laptop screens, a latte in one hand and a touch pad in the other. But many wireless users and businesses that provide the open network aren't aware of the risks to their personal information when connecting wirelessly.

"It's a very insecure world out there," said Danen Romine, a computer technician at Quidnunc, a computer, software and Internet store in West Seattle. "Within the last year, open networks have become extremely rampant. But to the home and small business user--they aren't very hip to the dangers."

Wi-Fi "hot spots" allow laptop users to surf the Net without plugging in and are typical in hotels, airports and coffee shops. During the last several years, wireless connections for home and business computers have become increasingly prevalent.

Wi-Fi uses unlicensed radio frequencies to carry Internet connections and can be accessed at a range of about 300 feet, said Mohamed Lahlou, owner of A-1 Best Computer repair shop in Ballard. Depending on how many people use a wireless network at the same time, Wi-Fi offers faster connections than dial-up or cable modems.

But using or providing an open wireless network not protected by a password can allow access to someone's personal files, and in some cases permit wireless "borrowers" to take control of an unsuspected user's machine, said Romine.

When connected to the same wireless router, such as those in Wi-Fi hot spots, computers are linked and recognize the open connection as legitimate for networking purposes, he said.

Files that are designated "shared" and located in places such as "My Shared Places" on Windows XP and the "Public folder on a Macintosh, are especially vulnerable between browsers who use the same network, or IP address, said Romine.

Though one can easily choose whether or not to make a file public, many average users aren't aware of those options, said Lahlou.

Every computer that corresponds through the Internet is assigned an IP address that uniquely identifies and distinguishes the device from other computers on the Web.

"When you are connected to someone's wireless router, you've associated yourself with that person's IP address--you're 80 percent there to getting into their files or hard drive," said Lahlou.

More advanced users could easily download software designed to intercept over-the-air communications, and while firewalls and other protective software can help keep intruders out, nothing is foolproof, he said.

Many of Lahlou's customers maintain their client's personal or financial information on computers with open wireless connections, putting all parties at risk of identity theft, he said. Lahlou encourages them to contact the router's manufacturer to add password protection.

"It's a very simple thing to do (to get a password), but so many people don't realize how vulnerable their computers and information are," he said.

On a recent repair call in the University District, Lahlou found more than 30 open wireless networks, all coming from nearby local businesses.

"If someone really wanted to they could easily get into (the businesses) shared files, or even their hard drive if they had the right kind of software," he said.

Mr. Spots Chai House and Ballard Sip and Ship provide free Wi-Fi but neither has warnings posted telling customers of the risks they take when connecting to a wireless network.

Paul Cramer, manager of the Sip and Ship, said none of his customers have ever expressed concern about wireless security, though he thinks it could be a liability for a financially vulnerable small business.

When the Sip and Ship first offered free wireless, their business computer used the same router as their customers. But they soon realized that their administrative files were easily accessible through the open network. The owners quickly installed a new router for customers and keep their business computer protected with a secure password.

"It seems obvious and plainly simple that you're taking a risk when connecting to an open network," said Cramer.

But these risks don't seem to stop people from connecting wirelessly all over the city. Seattle ranks No. 1 out of the top 100 U.S. cities that have the greatest wireless Internet accessibility, according to Intel Corporation's third annual Most Unwired City Survey.

The city provides free Wi-Fi at four downtown parks and the Columbia City and University business districts. Some Seattle Public Library branches also provide free wireless, including the Ballard branch. Users are warned that their data and communications could be subject to intruders and are encouraged not to conduct any financial transactions while connected to the open network.

"It's kind of scary for those with wide open connections," said Romine. "It could come back to haunt them."