I was very upset with 500px when they abruptly stopped allowing Creative Commons licenses and forced me to re-license my existing photos on the service. Frank

I was very upset with 500px when they abruptly stopped allowing Creative Commons licenses and forced me to re-license my existing photos on the service. Frankly I'm also slightly annoyed with Unsplash for reinventing the wheel with their own license instead of using standard CC licenses, reducing compatibility with other free culture projects.