Troll them back with ponies and tell them "I hear someone talking, but the sounds keep changing. Must mean nothing." Or something similar.
Edit: Ah, cr@p. I was reading down towards the end of the topic and didn't see about April Fools.
They made everyone an admin on my server. It was funny; everyone was like "WHO TO ABOOS FIRST!?"
Advice stands, though. Ponies are like troll repellent. xD
Also, I love mocha coffee. <3