I was going through the latest chapter and it just hit me. Well
we all know jiraiya left a code behind that states "The real one
isn't with them", so everyone gets the idea that the 6 bodies
are being controlled from one source.  Chapter 418 page 11  And
in the latest chapter there was a discovery, That scienctist
doctor women figured out that the black rod is a chakra
reciever. And the interesting part is that it's "still recieving
chakra"  Chapter 420 Page 16  And guess what this means
.....They can analyze the reception to figure out exactly where
the chakra is coming from. In other words, they can find out
where on earth nagato is hyding himself.  What do you think??