ArcheAge forums user "ArchegeDown" announced on Friday at the official forum that he can bring down any server he would like to. There was a big fuss and because nobody believed him, he simply proved it. Selected servers by the other forum users went down and after around 3 hours and 32 pages the Trion Community member closed it with his last words: "We're looking into this matter with the player. In the mean-time, however, I believe this thread has run its course, and am closing it."
It seems legit that there is indeed a hole in the system and players are able to crash servers if they discover how.