Who are the germa 66? Just finished reading the chapter 828 and I have to say the germa 66 has me blown away. 

Who exactly are they? Are they pirates? Are they nobility like the tenryubito? 

Did I miss a chapter or something? Can someone fill me in?
The answer below has pontetial spoilers, because the animated series hasn't catched up with the manga. Proceed with caution!

SPOILERS


   Germa 66 or Warmongers as they have been called is an
 organization which is controlled by Vinsmoke family, which
 recently we found out is Sanji's family. They have ties with the
 Underwold and recently with Big Mom Pirates, because of the
 marriage/alliance of Sanji and Purin.  As for the nobility
 Vinsmoke family as Reiju said even though they don't own any
 land, they are still participate at the Reverie
 *So to summarize, Germa 66 is an organization that is under the Vinsmoke Family and has a lot of weapons/technology at their disposal. They are not pirates and they have affliction with the nobles not directly but indirectly through Vinsmoke Family.
 This is all we know so far.


Anything that you might need to know is in the one piece wikia Germa 66