The undermine journal (http://theunderminejournal.com) is in violation of the API usage agreements for two reasons.
1. They refuse to expose the code related to the usage of the API. This is required as part of the usage policy.
2. They charge a fee for events notifications (sellers and market status). This is forbidden as part of the usage policy.
It is my hope that Blizzard contacts the undermine journal and brings their conduct in line with the requirements so that everyone can enjoy the environment they have created for free, as well as learning a thing or two about using the API.