A blogger was approached by a police officer and asked to leave a public park bench because of a Federal law prohibiting him from using Wi-Fi there: The officer told the gentleman that he couldn't use the Wi-Fi access, provided by the library, outside of the library because of a "theft of signal" law, which was recently explained to him and his colleagues by a secret service agent (scroll down to the August 22 entry here for the full account directly from the source).
Other comments posted on the blog indicate that I'm not alone in wishing that this guy let himself get arrested just to challenge the cop. It appears that the entire exchange was quite cordial, which is great, but clearly there is no such law and it would have been nice to find out what kind of information the officer was working on.
The other problem here is that the blogger had shut off his Airport card and continued to work offline but the officer wouldn't allow that either. Since the incident, the library has posted a sign that says the Wi-Fi network is only available a half-hour before and after operating hours. There are two issues with that policy. The first is that if the network is available when the library isn't open, users would have to be sitting outside, just like the blogger. It will be interesting to see going forward if people get approached for sitting outside on their laptops. The other issue, which affected the blogger, is how law enforcement can determine if laptop users are online or offline.