Car Phone Numbers

When you are walking around the small streets of Korea, there are usually lots of cars parked every which way.  I've noticed there is almost always a phone number in the window.  Some are just scribbled on a piece of paper, but there are also pillows with the phone number embroidered onto it.  People put their phone numbers on their car so that if they block in someone, the person can call them and get them to move!  Back home I would be afraid of random people calling me or putting my number on some call list, but here its normal!