The system where someone monopolizes a essential good and leverages that to gain power is called anarcho-capitalism and is a whole different thing. In anarchy, ownership on that level does not exist. Neither a company nor a person can own a factory, or a farm, or the power grid. Employment doesn’t exist. People can band together and distribute tasks for a common goal (such as producing a certain good) but they all hold equal stake in all decisions.

Of course a group of people could use violence to oppress other people. But then you no longer have anarchy. The same way a democracy stops beeing a democracy once a group seizes power and doesn’t allow fair elections anymore.

It becomes a whole different thing when you yourself are a creator of any kind. Sure you can retorrent TBs of movies. But you can’t retake that video from 3 years ago. I have about 2 TB of photos I took. I classify that as media.