Wi-Fi has freed computer users from wires at home and on the road, but that freedom comes at increased risk of attack, experts say, as unsecured Wi-Fi networks have become a favorite target for hackers.

In one recent example, a local cafe found its free Wi-Fi connection had been used to send spam. In Phoenix last year, a home Wi-Fi network was used to fraudulently order merchandise.

So far, there's little data on Wi-Fi hacking, partly because of its stealthy nature.

"We don't really know how big the problem is, to the extent that people don't even know they've been compromised," said FBI Special Agent Tom Liffiton, Phoenix-based coordinator of the agency's InfraGard security program. Full Story...