For the past 4 years, I mostly worked on what I could, not what I really wanted...
Happily, sometimes there was a overlap, but how it is not slavery?
I cannot quit. I cannot choose what I will work with (mostly, every time I was without a job, I had to accept whatever offer came by, the few times I tried to be picky I ended even more indebted to buy food). I cannot live where I want... And so on.
With some employers, I did feel owned, because even if they did not knew I was in deep debt, they could push me to do whatever they wanted, just with a small treat of dismissal, because I CANNOT afford be dismissed, my debt payment is way above the country average wage, and for the last years I've been living reaching the end of each month slighly indebted or with a zero balance in the bank.
I dread the day I suffer some accident, near my home people ignore the red light a lot, and I think if I ever get hit by a car, I don't have money to pay medical expenses. (my parents are also in debt, partly by their incredible education expense they had with me, sometimes taking loans they knew they could not pay just to pay for my schooling).
Right now I am co-founder in a startup, and every time our cash starts to run low, conflicts flare up quickly, because the pressure becomes immense, it generates lots of instability, and I already lost two relationships over this (ie: not over having a startup, but having those debts and financial instability and extreme dependance on employers).