Global Positioning Systems, satellite-based navigational systems, have increased in availability over the past few years, and as they become more accessible thieves are taking advantage of increased opportunity. In Islip, NY, according to Newsday, 55 GPS devices were stolen from town trucks over the past week. The trucks were parked overnight in locked and fenced highway department vehicle yards. The stolen units retail for $50-$75 each, an official reported. The units make it possible to monitor vehicle speed, location and direction. The Star-Telegram reported that in Fort Worth, Texas, thieves are grabbing GPS devices at such an overwhelming rate that police are recommending drivers stop leaving them in their cars. Over the past two months, around 10 units have been stolen each week, according to police. Since the beginning of this year, about 268 units have been reported stolen in Fort Worth. Many of the thefts have occurred in apartment and hotel parking lots. Thieves will break car door locks, smash windows or simply reach through an open window to covet the device, and cops say it only takes a few seconds.