The open source license being used by magicpedia seems really clear on this.
Even Joe P. agrees. This is how such open source "viral" licenses operate. There's no infringement when copying is explicitly allowed by license as in this case.
Wikipedia operates the same exact way, under the same exact license, even offering full downloads of their site for those who want it for whatever reason.
Here's the longer legalese
of the license used by magicpedia.
3. License Grant. Subject to the terms and conditions of this License, Licensor hereby grants You a worldwide, royalty-free, non-exclusive, perpetual (for the duration of the applicable copyright) license to exercise the rights in the Work as stated below:
A. to Reproduce the Work, to incorporate the Work into one or more Collections, and to Reproduce the Work as incorporated in the Collections;
B. to create and Reproduce Adaptations provided that any such Adaptation, including any translation in any medium, takes reasonable steps to clearly label, demarcate or otherwise identify that changes were made to the original Work. For example, a translation could be marked "The original work was translated from English to Spanish," or a modification could indicate "The original work has been modified.";
C. to Distribute and Publicly Perform the Work including as incorporated in Collections; and,
D. to Distribute and Publicly Perform Adaptations.
This is why it's not good to use open source licenses unless one is fully cognizant of their ramifications.
Joe P. can hope that someone using the license will work with him, but under the license chosen for magicpedia, he has no real expectation in that regard. In the open source world, these "forks" of information often include little or no communications/collaboration of this type. It's just not that unusual.
If the creator of magicpedia wanted/needed more control over distribution of its content, that person should certainly have chosen a less permissive license.
If RK got this site taken down, all he would have to do is file a DMCA counter-claim and the material would go right back up.
With the licensing being so clear, it seems to me that such counter claim would probably be honored.
If the subscriber serves a counter notification complying with statutory requirements, including a statement under penalty of perjury that the material was removed or disabled through mistake or misidentification, then unless the copyright owner files an action seeking a court order against the subscriber, the service provider must put the material back up within 10-14 business days after receiving the counter notification.