In 2012 he was able to pull more coins out of his accounts than he had deposited because of a vulnerability in the dark-web market. The affidavit describes how he registered several accounts on the site with names like "thetormentor" and "dubba", deposited a sum of coins into the Bitcoin wallet for each account, and then made repeated withdrawals of the entire sums held there. The Silk Road had a bug that allowed rapid-fire withdrawals without first making sure that the requested money was in the user's account. According to an affidavit signed by an IRS-CI special agent, Zhen was able to move at least 50,000 Bitcoins out of Silk Road in a few days.
In the nine years that followed, the windfall appears to have been left almost entirely unspent because of the fear of law enforcement. IRS-CI investigators traced Zhong's coins to his accounts on an unnamed cryptocurrencies exchange, which showed his identity. The Silk Road hacker, referred to in court documents only as Individual X, took nearly 70,000 bitcoins from the site and held them for seven years after exploiting a vulnerability in it. The charges against Individual X haven't been made public. A wire fraud conviction can carry as much as 20 years in prison.
The creator of the Silk Road, Ross Ulbricht, was sentenced to life in prison and ordered to pay $183 million in damages after the site was destroyed. Ulbricht's debt was paid off in full in exchange for his agreement not to lay any claim to the remaining money, in a strange twist to the Silk Road seizure.
It may seem like a strange way to pay off the Silk Road's creator, but it's true. There is a lot to go around in an era when the US Treasury gets a lot of money from IRS-CI cryptocurrencies seizures.