The bosses who tell them how to use it have authority.
The landlord whose name is on the deed has authority.
Anarchism is not a rejection of power itself. There are so many kinds of power we affirm: the power to provide for ourselves and one another, to defend ourselves and sort out conflicts, to perform acupuncture and steer a sailboat and swing on a trapeze. We prize the freedom to develop our capacities and capabilities, especially in ways that increase others' freedom as well. Every time one of us acts to achieve her full potential it is a gift to all.
The bluest eye, the deepest voice, the thinnest waistline.
Just in time for Rolling Thunder #8, we've produced a new sticker on this subject. Screen-printed on vinyl and 4" in diameter, they are going out free in every single order.
For a nuanced discussion of various forms of power and authority, one could try Uri Gordon's Anarchy Alive; an expanded version of the relevant chapter is available in pdf form here. Uri is currently touring North America.