It depends. While there are many who deliberately do this to be jerky (and that's simply annoying), I have taken into consideration that there are a few who may have to have their music a little louder than normal because they can't hear well. Even though I'm not hard of hearing, I still have a special sympathy for those who are. However, people who are hard of hearing should refrain from playing their stereos while they're driving -- that way they can concentrate fully on the other sounds around them. When they are parked someplace and sitting in their cars, then they can play their music. For those who hear fine, there's absolutely no excuse at all for this.
