D--> I've seen this happen with other well-known, long-term groups. I've seen people make group copies of iRawr, TEC, TDC and so on.
D-->This sounds like one of those cases of a butthurt reject trying to get back at the group that denied him/her the privilage to join by making a copied group. Seems like their little plan of angering the group members has worked since you bring it up on the forums.
D--> There's really nothing you can do to stop them from doing this, since there is no rule stating that people cannot copy other groups. However, you can block this person and report them if they start breaking any kind of game rules. The best thing you can do is block and ignore them, and not try to show how upset you are. It will probably make them more satisfied to see how upset you are. More than likely this immature copy cat person will grow bored of their little trolling game and call it quits.