They're all over RS, I was there with JMod Slayer when one came down at G.E and landed on us, pushing us away Freaky shit, my first thought: Sara is pissed off or zammy took a dump.
It's kind of obvious if anyone reads the homepage. They said something about Clan Citadels, and if you look at the concept art, and compare what the lumps look like, then it looks very similar to what could be a Citadel. Makes ton of sense to me.