It needs to be a balance between being friends with your children and disciplining them. They need to confide in you, but also respect you as an authority figure. Swaying too far to either side can result in various problems.
I feel too many parents these days are worried about being friends, and do 0 disciplining of their children. Kids these days have little respect for anything.
Good topic, and good post.
I would agree. You need to be there for them and show support like a friend but if they are crossing a line you need to let them know that the line exists for a reason. As a parent you are, in the end, the decision maker.