Seattle Times, May 27, 2002 - Wi-Fi 'hot spots' allow laptop, PDA user to be covertly tracked

From Article:

“Your average person does not know that they are transmitting any sort of serial number or identification code,” says Dana Spiegel, a volunteer with NYC Wireless.

For individual users on a public network, it’s best to work under the assumption that the network is completely insecure and perhaps even “hostile,” says Spiegel. “That means using only secure channels for your communications, which is something that we always encourage our users to do.”