Again going by reading the above posts, he was helping FBI & insurance company guy. Not sure how they are shown. But as a general measure,it seems he is helping legitimate guys. Well, in general working for FBI guys & a major company to prevent theft/fraud would be considered doing good?
The revenge part seems to be inspired by the Saw franchise, wherein Tobin Bell also targets people directly or indirectly responsible for affecting him
Or maybe even Anniyan/Aparichit starring Vikram where his father contends in court that several people need to accountable for his daughter's death as it was their negligence/selfishness/laziness etc which was responsible.
Plus I think he was a former magician in the movie so he broke the magician's code 
This is where the difference lies. He was helping the bad guys who stole money from common people. Con men got them all to their show where they blanked the bad guy's bank account and transferred all the money stolen from the common people to their accounts. In real world, that would probably be massively illegal and I can imagine that the authorities would ensure that all those transactions are reversed and so on. :tongue:
