I don't think it's actual hacking. I bet, it's more about phasing. I did encounter this in Icecrown, where are several layers of phases. I wanted to get some saronite and it often disappeared even though nobody seemed to be around. After doing some quests I found myself being in a different phase, but in the same area. The nodes remained where they were, and some hordeplayer was flying around gathering them.

--> The nodes are available from any phase and are not being separated out.