War Driving
Apparently there’s a new hobby (well, new to me) being taken up by geeks around the world called War Driving, which is the “fine art of finding and marking the locations and status of wireless networks.” This is presumably to make it known for others who want to piggyback your wireless connection to the Internet (and who knows what else). Your best defense is obviously to password protect your wireless network. Beyond that, stay on the watch for slow moving Volkswagons (or Hybrids if they have jobs) in your neighborhood and keep those paintball guns at the ready!