Scrobbing is the act of running a program that tracks what songs you are listening to and uploads them to a social network such as the website that coined the phrase, Last.fm
This is a voluntary action and though it sounds like an invasion of privacy, the users consent to scrobbing so they can compare music tastes with the community and friends.
1. 'I've been scrobbing for weeks and I've finally listened to 10,000 tracks'
2. 'I haven't updated my playlist for awhile and when I afk
from my computer I end up scrobbing songs by artists I don't like, I hope my friends don't see'