I was able to root my Arc S (but UK model/unlocked). I seem to recall using this...

		kamjam on Aug 12, 2013 \| parent \| context \| favorite \| on: You Might Have an Invisible Facebook Account Even ... I was able to root my Arc S (but UK model/unlocked). I seem to recall using this method, but would need look on my PC for the files i used to verify... http://theunlockr.com/2012/10/09/how-to-root-the-sony-xperia...