[These cases have been closed. If you would like to appeal the decision of the hunter please open a ticket on the help page and the case will be looked into by a second hunter.]
Everything was in game chat. It sucks that players resort to such tactics; but in that case, it worked for yellow (who came up with the entire idea to gain power).
Unless you are saying they coordinated via another website, in private; then that's cheating. But using game chat for it is just part of the game. A crappy part, but a part none the less.