Who are the hackers caught in Bitfinex?

Who are the hackers that have been apprehended in connection with the Bitfinex hack? Are they known individuals with a history of cybercrime, or are they relatively unknown actors? What methods did they employ to carry out the attack, and what was the extent of the damage they inflicted on Bitfinex and its users? How were they eventually tracked down and apprehended by law enforcement authorities? What legal consequences are they facing as a result of their actions?