The GPS system that helps you get around easily is also a big help for policemen and divorce lawyers. The electronic breadcrumb trails left by many GPS systems - add-on or built-in - may be used to track where the car has been and it's started to be used as a tool for investigators. It's already pretty well established that the electronic components in your car can rat you out and be used in court. (The officials may need a search warrant.) The right against self-incrimination doesn't extend to things you own or drive. Actually, there are multiple ways the electronics in your car can get you in trouble. They include:

-- GPS devices may keep a trail of where you've been (and when), called breadcrumbs (as in Little Red Riding Hood), that you may or may not be able to disable. Also, all keep a list of recent destinations that you've entered.
-- The data recorders in your car track the last couple seconds before an impact: speed, brakes applied or not, possibly whether the car was skidding, force of impact. Some of it might be useful to help send the right amount of medical help, if it's connected to a Mayday calling system. But it can also be used by an automaker to defend itself in a liability suit (driver he was doing 65 mph, black box says 88 mph when the tire blew).
-- Your telematics system, such as GM OnStar, BMW Assist, or Mercedes-Benz TeleAid, can remotely track your location in the event your car is stolen, but these systems have also been used - or attempted to be used - by unhappy spouses who think their partner is stepping out on them. Now, in most cases if you want to know the current location of your allegedly missing vehicle, you have to file a stolen car report with the police. GM has enough woes already without getting caught in the middle of messy divorce cases.

Some recent examples of GPS being used to track down criminals were cited in The New York Times. In New Brighton, Pa., a man was charged with torching his own house when the GPS indicated it was about 100 yards away at the time the fire was set (and he apparently claimed to be far away). In Butte, Mont., the GPS of rape suspect Brian D. Adolf showed he was prowling around town just before the incident; he copped a plea before going to trial. In Chicago, Eric Hanson's GPS showed his whereabouts after his parents, sister, and brother-in-law were killed in 2005. Hanson was sentenced to death.