Gary Schaffer looked out his window recently to discover a reporter standing on his lawn, pirating his wireless Internet access to test a new mobile phone.
The phone, made by Belkin, is one of several new mobile devices that allow users to make free or low-cost phone calls over the Internet.
They are designed to take advantage of the hundreds of thousands of wireless access points deployed in cafes, parks, businesses and, most important, homes.
The technology's advocates say that as long as people are paying for high-speed wi-fi access in their homes, they should be able to use it as a conduit for inexpensive calls and an alternative to traditional phone service.
But, in a twist that raises some tricky ethical and legal questions, the phones can also be used on the go, piggybacking on whatever access points happen to be open and available, like that of Schaffer.
A retired business teacher, Schaffer seemed affably cautious about the idea of having his bandwidth borrowed.
"If you're a friend, I'd say, let's give it a try," he said. "If you're a stranger, probably not, unless you had to make an emergency call."
For all its limitations, the technology is starting to emerge commercially, with companies like Vonage, Skype (owned by eBay) and T-Mobile (a unit of Deutsche Telekom) now selling or supporting mobile devices that use wi-fi networks.
But some carriers are not convinced that the technology is ready for the market.
"We can totally understand that people want even more ubiquity from cell phones," said Jeffrey Nelson, a spokesman for Verizon Wireless. But wi-fi devices "aren't where they need to be," he said.
The proliferation of wi-fi laptops and, in turn, hunters of free Internet access, has already raised questions about whether borrowers of bandwidth are breaking any laws.
"There's a big debate going on right now," said Jennifer S. Granick, executive director of the Center for Internet and Society at Stanford Law School. Granick said some people think that using a connection without permission constituted unauthorized access to computers, which is a crime.
Traditional analogies are hard to come by, she said, adding that she does not think using wi-fi is the same as trespassing, since the signals travel beyond property limits.
"People say that you can't go inside somebody's house; but I say, you can sit outside and listen to the radio," Granick said.