Today’s WSJ has a story that vividly illustrates the tradeoffs that technology can offer between privacy and security (subscription required). The story explores how the increased data that cars collect can be used:

That data could be crucial to guiding an ambulance crew’s decision about whether to rush you to a fully-equipped level one trauma center, says Dr. Richard Hunt of the Center for Disease Control. Research by the CDC has shown that a severely injured person who is transported quickly to a level one trauma center has a 25% better chance of survival.

“I know from clinical experience as an emergency physician, this is a life or death decision,” Dr. Hunt says.

But what if, after you survived the wreck, that same technology turned tattle-tale, and divulged to police or the insurance company that you were speeding or driving recklessly?

That same data can also be used to save you money.

In Michigan, Minnesota and Oregon, Progressive offers a discount of up to 25% on your car insurance for letting them track you. The TripSense connects to your car’s on-board computer and records data on how fast, how far and what times you drive. The technology lets them rate risk in ways never before possible – for example, greater discounts if the bulk of your driving is between 3 p.m. and 6 p.m. on weekends.

If you drive more than 75 mph more than 0.75% of the time, you get a negative 5% discount, which can offset the other discounts. Progressive claims that “your data will never cause your rate to increase.”