OK form a Union, I'll be the leader and you will have to support any decisions I make which may effect you financially, whether or not you agree to them.
There you go, that's why a union would never work, we are all independent and as such we will each make our own decisions on how we run our business.
What iStock has done is very bad news but mass hysteria calling for forming a union is just a waste of breath.
Lots of people have made suggestions on how to react to iStocks commission drop, as an independent you have the luxury of being able to act on one or all of the suggestions.