On June 16, U.S. District Judge Gary Feinerman of the Northern District of Illinois ordered former Mt. Gox CEO Mark Karpeles' motion for summary judgement. The lawsuit was first filed in 2014 by Gregory Greene, a user of the exchange.

Karpeles had maintained that the plaintiff had brought in a set of new allegations and the arguments had been changed. Judge Feinerman said that the new arguments had “merely added detail with the aid of discovery” and that it did not “violate the rule against altering the factual basis of a claim on summary judgment.”

The lawsuit claims that the safety of users’ funds were falsely represented by Karpeles, which the exchange’s terms of services having claimed that it would safely store users' assets. However, Karpeles states that Mt. Gox did not have a terms of service. Greene had allegedly lost 42.9 Bitcoin (BTC), worth approximately $404,000 today.

Greene’s lawyers were pleased with the judge’s decision, saying in an interview with Law360,

We are pleased with Judge Feinerman’s decision. By his own account, Mark Karpeles withheld critical information from and took affirmative steps to defraud Mt. Gox's investors.

The hacking of Mt. Gox exchange is one of the most notorious incidents in cryptocurrency history, with over 850,000 Bitcoin having been stolen from its hot wallet in 2014. At that time, this was worth roughly $450 million. Roughly 200,000 Bitcoins have since been found.

In March 2019, the Tokyo district court found Karpeles guilty of data manipulation, handing him a suspended sentence of two years and six months. The former Mt. Gox CEO had escaped the charges of embezzlement and breach of trust, and vehemently stated that the incident was not the result of any illicit intentions on his part.

Karpeles is currently working on a new Blockchain Operating System business in Japan.