About a year ago, Michael Kierans began offering free wireless Internet access at two of his Káva Káva Káva coffeehouses to attract business. Word spread and the cafés filled with new customers with laptops — or so he thought.

Wireless Internet access, often referred to as Wi-Fi, certainly drew people into his cafés, but Kierans soon discovered that many users abused the service and parked themselves for hours while purchasing little or nothing at all.

"The majority of our Wi-Fiers are reasonable people who realize that if they are occupying commercial space in a café, they should be spending appropriate amounts to justify their use of space and facilities," Kierans says. "Unfortunately there are exceptions that set bad examples, and it does hurt us when the weather is bad and people can't sit outside."

On a recent visit to Kierans' café off Národní trída in Old Town, laptops perched on four small tables inside, their owners typing away. Outside, two more laptop users occupied tables.

On inclement days, Kierans said, customers prefer indoor seating, but they often turn away because the place is full. Many of the tables' occupants are what he describes as free downloaders — customers who take up entire tables that would accommodate two or three people — and purchase only a 35 Kc tea over the three or four hours they work on their laptops. Kieran complains that on these days his free Wi-Fi ends up costing him more than he had bargained for.

Wi-Fi providers are constantly on the lookout for opportunities to bring the technology into Prague's restaurants, bars and coffeehouses. Those who sign up for the service — paying from 5,000 Kc to 15,000 Kc ($210–620) a month — face the challenge of trying to incorporate it into their business models to help, not hurt, their bottom lines.

Many, such as Tulip Café on Opatovická street, opt to charge for Wi-Fi access. Tulip requires customers to buy a voucher good for online time — say, 50 Kc for one hour — or open an account directly with its Wi-Fi provider, who gives the business a small percentage of each transaction. But there are other cafés, such as Kierans', that offer it free in hopes of drawing customers who will then buy food and drink.

Roxy on Dlouhá street began offering free Wi-Fi in 2003. Manager Marek Lakomy´ said Roxy has an unspoken rule: After half an hour, customers are expected to purchase something. But they don't always follow that.

"We don't force people away if they don't [buy something]," he says. "Some are able to sit there for an hour and a half without ordering and feel upset when this is pointed out to them."

Nonpaying Wi-Fi users are more of a problem in the United States, where 41 percent of the country's 8,500 cafés that offer Wi-Fi do not charge for it, according to MetroFreeFi.com, a Web site that tracks free wireless access.

However, users can find free Wi-Fi signals outside, too — those that spill over the property boundary of the provider. Such areas are referred to as hot spots. In the United States, entire blocks are turning into hot spots in some cities.

Czech Information Technology Minister Dana Bérová estimates there are more than 350 hot spots in Prague and more than 500 total nationwide. The ministry, however, does not track how many offer Wi-Fi for free, or how many of them are located in cafés or restaurants.

Max Munson, who owns the Jáma pub and restaurant on V Jáme street, has had a much different experience with Wi-Fi users.

Jáma began offering free Internet access at several computer terminals located in the rear of the restaurant, with free Wi-Fi from 2003. "Laptop users are 99 percent less likely to freeload," Munson says.

However, he suggested that some of the customers using the computer terminals were free downloaders because they sit for hours without buying anything. So Munson began selling Internet access time by the minute, like any other Internet café.

Jáma, too, has an unspoken rule governing Wi-Fi users: Customers are expected to purchase something every hour or so. But, he said, the rule is not enforced.

"There could be a guy who sits there and uses Wi-Fi for two hours and just buys a coffee. Obviously that's not ideal," Munson says. "But then he brings two of his friends in to show them the Wi-Fi, and they end up ordering lunch and drinks."

Business owners say there is a fine line between spoken and unspoken rules, and they run the risk of driving away customers if they are too rigid.

Káva Káva Káva's Kierans used to charge Wi-Fi customers when his stores acquired the technology about three years ago. He said the provider then, Cesky´ Telecom, proved too expensive. He switched providers and was able to offer free access.

Kierans doesn't want to go back to charging Wi-Fi customers, but he is considering it. A new American wireless company is vying for his business, and Kierans is thinking about signing on. He also is pondering whether to start a Wi-Fi access club.

"I think that as the use of laptops to connect to wireless networks increases ... the free-downloading problem increases," Kierans says. "It is getting very close to the point where some action will be mandatory."