Exploitation of voluntary workers has a long, long history. It's basically the reason why unions came into existence, and employment laws. For example, in time

Exploitation of voluntary workers has a long, long history. It's basically the reason why unions came into existence, and employment laws. For example, in times of high unemployment, I could tell my workers that if they want to keep their jobs, they will work unpaid overtime, or take a pay cut, or give me a blow job, or work without adequate safety gear. These kind of Hobson's choices are real things that really happen. I frequently see a less explicit exploitation of voluntary workers in companies; when a company encourages a culture of long hours and not taking holidays, they're getting extra hours for free from their voluntary employees (take your holidays, people).