There have been several stories in the press lately of hackers breaking into home wireless networks and using them to download porn - effectively using the internet connection of the people who own the network. For the most part, these attacks are successful because when the wireless networks were set up, the built in security was not even installed. therefore the networks were totally unprotected. There is a series of articles on e-Week that provides some good info on wireless security at Dealing With Gaps in Wireless Security