Businesses in New York's Westchester County that offer public Internet access, as well as those that conduct their own business over wireless networks, must now install a firewall or other computer security measures, under a new law.

The law, signed by county executive Andy Spano on April 20, states that any company that electronically stores or utilizes personal information, or provides Internet access such as wireless "hot spots," must take minimum security measures to prevent unauthorized wireless access to this information within six months. County officials say they believe the law is the first of its kind.

"People don't realize how easily their personal information can be stolen," Spano said in a statement. "All it takes is one unsecured wireless network. Your credit card number, social security number, bank account information -- it's all vulnerable if a business that collects that information hasn't taken the proper steps to protect it."

While use of public Wi-Fi skyrocketed 43% last year, according to JupiterResearch, laws like Westchester County's may help convince those slow to adopt the technology. "We asked consumers what concerns them or prevents them from using public Wi-Fi," Ina Sebastian, a Jupiter associate analyst, said in an e-mail. "Twenty-one percent of online consumers were concerned about security."

Back in November, when Spano introduced the bill, a team from the county's Department of Information Technology took to the streets in downtown White Plains with a wireless laptop, searching for vulnerable networks. During a half-hour drive, they found 248 wireless hot spots -- almost half of which lacked any visible security.

"Identity and data theft is clearly a local threat here in Westchester," Spano said.

Installing a network firewall is the easiest and cheapest way to abide by the new law, according to county officials. Other alternatives can be found on Westchester County's new identity theft website.

"This is an educational process first and foremost," said Elaine Price, director of the Department of Consumer Protection's Division of Weights and Measures in Westchester County. "This isn't a cost from keeping [these businesses] from offering free Internet."

Because installing a firewall is relatively inexpensive and quick, Price said she doesn't foresee businesses having any problems with the new law.

"We're hoping this will become a trend," Price said.

The law will be enforced by the Westchester County Department of Consumer Protection's Division of Weights and Measures. The first violation will result in a warning where the offender will have 30 days to comply with the law. A second violation will cost the business $250, while further violations will result in a $500 fine.