In the CIA Database section of the Black Ops wikia (http://callofduty.wikia.com/wiki/Centra ... ata_system), there are two letter strands in relation with DERRIESE that were formed using specific letters in the limericks. The strands are:
MIBAWIHTIYDMKMFKSWTWU (Decodes to EIE)
MJTBITMBIAWISHTIYDKMFKSWU (Decodes to E T)
I dug around in these strands and noticed some interesting sections...
Lets start with the second strand:
The first bit starts with MJTBIT. Well Majestic 12 (aka Dreamland) is also known as MJ12. A tbit, or terabit, is 10^12 bits...
Next you have MB, which could stand for something like monkey bomb (considering the references to John Banana)
The part that I am most curious about is at the end: DKMFK. D. King's initials are DK, and his login password is MFK
I'm still working on it, but I wanted to throw these thoughts out there