Hmmmm..... I sort of think of Amon as the Joker from Batman, which interesting side note( Mark Hamill voice Lord Ozai and the Joker), anyway my point is like many others have pointed you can't trust Amon's backstory. His mind is warped for goodness sakes he believes that spirits talk to him and we all know that the Avatar is the link between the spirit and real world. He's an Extremist who is Insane making him Extremely Insane. So here are the most of speculations I've seen on Amons Identity and what my thoughts are.

1. Amon is the boy from Zuko Alone. Many people have discounted this theory based on age, saying that Lee would be about 80 years old and it would be impossible for Amon to be so powerful and that he is way younger. First of all General Iro was extremely powerful and old, King Bumi was extremely powerful and old (100+), plus a direct quote from Amon stating his age has never occured and we haven't seen his face so we don't know that he is in his thirties. I think this is plausible.

2. Amon is Tarlock. I personally think Amon is using Tarlock's mad hunger for power and control against him. Possibly Tarlock is working for Amon that would explain how he knew where chi blockers were training, and why Tarlock wants team Avatar out of the way and becomes so angry when Korra stops the escaping equalists in episode 8. I don't believe they are the same person based on the episode where Korra goes to fight Amon on Avatar Memorial Island. Tarlock was standing with Tenzin, how would he slip away from Tenzin get to the island, interact with Korra, and then get back to where he and Tenzin where standing originally without Tenzin noticing. I think Tarlock and Amon are definitely connected through Yakkone though.

3. Amon is Aang's son Bumi. Pppppffff.... I think the creators of this amazing series would be less one dimensional than, (The villian is the jealous son of the original hero).

I think Amon is a bender of some sort who has studied chi blocking and chakras. Through the spiritual training of bending his knowledge of chakras could make his chi bending immensely powerful. This series focuses on the spiritual vs. the physical. In the theory of Tarlock and Amon being Yakkone's sons, Tarlock is definitely the physical( through blood bending Tarlock has complete control over someones physicals form and he uses physical laws and force to take power away from non benders) Amon would be the spiritual son of Yakkone (through chi blocking Amon controls someones spiritual abilities and making it impossible to bend and he allows Tarlocks physical restrictions to back fire and bolster the spirit of equalist and cause even greater tension between benders and non benders. If Amon and Tarlock are brothers Amon would know Tarlock very well and would be able to plan Tarlocks next move and play him for a fool or the brotherly bond could make them perfect allies in a quest to take over the world and be the only two benders left.

When Korra said to Tarlok "Your just like Amon" Torlok got all freaked out his eyes got a shocked look. It seemed like it was something someone had told him before and he had hated it and in his mind portrayed himself as someone completely different than Amon.

or With the Amon and tarlok being brothers theory maybe tarlok was always compared to amon and hated it.

or it just proves that tarlok has something to do with amon

(just throwing out random thoughts here)

I have a high suspicion Amon is a descendant from either Emperor Ozai, or Azula. Ozai is the only one known to have been incontact with this ability of taking away bending powers. Aang might have spilled this knowledge over to Ozai. The whole burned by fire story is made up. That is the reason for hiding his face.

I alsosuspect Korra is a grandchild between Katarra and Zuko. Those deepblue eyes of Korra are a dead give away. Plus those two had a vibe between them going on I guess either one of them found too hardto resist. It can also explain why Korra has difficulty obtaining the air abillity.

Well we know for a fact taht Katara married and had kids with Aang. And blue eyes and tan skin and all those features are chracteristic of a lot of water tribe people.

i don't think Amon removed those benders powers. it's fake. look at his behavior. he had a chance to take tenzin and bafong's powers and didn't. notice he took some people who were bad guys and might have been paid. i also think he was the fire bender that hurt people and aang took his powers.