motorhaven - 1:46 pm on Sep 5, 2012 (gmt 0)
Anything in the 23.21.180.__ range with a Via: header of "Onavo" is the Onova product for iPhone and Android. Its a compression service which speeds up mobile browsing. I'm keeping a close eye on it, but for now it appears to be legit users coming through this. The X-Forwarded-For header also properly contains the real user's IP address.