I personally believe it is councilman Tarrlok because he wanted to lead the task force against Amon. And since he is leading the task force he can call upon Korra for anything but marshale he raid a chi blockers place umm hello he knew that they would not catch Amon and do u think he would just leak information like that? I mean Korra was suppose to fight Amon on Avatar Island but he never showed up until he had her knocked out and told her,she would be the last to have her bending took away.Now Amon wears a mask,mask are use for people who don't want anyone else to find out who they really are and Amon is a aliest.He can Become Tarrlok and be all lets get Amon but then again he could be Amon and know everything about how to straight Republic City's Citizens to join him.maybe is wants to be the only bender so that he can rule the world?I mean look at the presented evidence upon him he is a councilman meaning he will know every attack against Amon(him) and also he leads to task force so he is safe no matter what. and he also presented the idea of a task force to the council i mean thats a lot of evidence that he could be Amon also one more important thing when Korra was suppose to fight Amon(aka could be Tarrlok)Tarrlok told Tenzin i have police boat and choppers near the island if anything goes wrong now think about that and then about the Chi blocker they took Korra and if Tarrlok had his people there Amon would not have attacked. Now look i said he is task force leader so he could have lied to Tenzin. i mean with so much power he could be Amon he has the perfect resources to be him and make the revolution happen.
Please post you idea about who you Think Amon is Thank you