Imagine if there was a law designed to curb home break-ins that required residents to lock their doors at night, but no one bothered to check any of the windows. How many burglaries would that really stop?
According to an article on Ars Technica, Westchester County, New York (where I grew up, coincidentally) passed a law that will make it illegal for businesses to have open wifi networks.
Supposedly this is all to stop identity theft.
I don’t have any scientific data to back this up, but from where I’m sitting it looks like more identities are stolen because people fall for stupid phishing scams than from hackers sitting in their cars with packet sniffers. If a determined hacker wants to break into a system that has personal information, the wireless network isn’t the problem.