I can't remember the name of the area where this takes place, but it's somewhere in the Cosmodrome in Old Russia where all the broken down helicopters are. There is a cave that infinitely spawns Thrall and Acolytes and has recently become THE place for loot farming. If you're in the area, you might notice a group of people (or many groups of people) camping on top of a concrete pillar, shooting down waves and waves of Hive that spawn in a small cave near the crashed Hive ship. I have a friend that goes there frequently and tells me that after about an hour of loot farming in this location, he managed to pull in 100+ weapon parts, 100+ (whatever armor material Warlocks use) and ranked up his Cryptarch 2 times. Just some information I thought I'd share. Also, if you happen to pass through this area and see some Guardians farming for loot, whatever you do, don't sprint over and start dancing in the entrance of the cave where the Hive spawn. Because the Hive won't spawn until you leave, and the people who are trying to farm for loot will send you very mean messages.