The answer seems to me to be a class action lawsuit. You can't just keep changing the terms of service. They are allowing news sites, which make money and are very much commercial, to use the (your) content for free. I don't think any of us signed up for that. I stopped contributing to iStock a long time ago, it just stopped being worth the hassle. The several hundred images that are there are old but still make a little bit of money, so I am not complaining. But I am certainly not going to give them any more images that they can give away.