GBL, a Chinese bitcoin trading platform, suddenly shut down on October 26, 2013. Subscribers, unable to log in, lost up to $5 million worth of bitcoin.
In February 2014, cryptocurrency made headlines due to the world's largest bitcoin exchange, Mt. Gox, declaring bankruptcy. The company stated that it had lost nearly $473 million of their customer's bitcoins likely due to theft. This was equivalent to approximately 750,000 bitcoins, or about 7% of all the bitcoins in existence. Due to this crisis, among other news, the price of a bitcoin fell from a high of about $1,160 in December to under $400 in February.
Two members of the Silk Road Task Force—a multi-agency federal task force that carried out the U.S. investigation of Silk Road—seized bitcoins for their own use in the course of the investigation. DEA agent Carl Mark Force IV, who attempted to extort Silk Road founder Ross Ulbricht ("Dread Pirate Roberts"), pleaded guilty to money laundering, obstruction of justice, and extortion under color of official right, and was sentenced to 6.5 years in federal prison. U.S. Secret Service agent Shaun Bridges pleaded guilty to crimes relating to his diversion of $800,000 worth of bitcoins to his personal account during the investigation, and also separately pleaded guilty to money laundering in connection with another cryptocurrency theft; he was sentenced to nearly eight years in federal prison.
Homero Josh Garza, who founded the cryptocurrency startups GAW Miners and ZenMiner in 2014, acknowledged in a plea agreement that the companies were part of a pyramid scheme, and pleaded guilty to wire fraud in 2015. The U.S. Securities and Exchange Commission separately brought a civil enforcement action against Garza, who was eventually ordered to pay a judgment of $9.1 million plus $700,000 in interest. The SEC's complaint stated that Garza, through his companies, had fraudulently sold "investment contracts representing shares in the profits they claimed would be generated" from mining.
On November 21, 2017, the Tether cryptocurrency announced they were hacked, losing $31 million in USTD from their primary wallet. The company has 'tagged' the stolen currency, hoping to 'lock' them in the hacker's wallet (making them unspendable). Tether indicates that it is building a new core for its primary wallet in response to the attack in order to prevent the stolen coins from being used.
On December 6, 2017, more than $60 million worth of bitcoin was stolen after a cyber attack hit the cryptocurrency mining platform NiceHash (Slovenia-based company). According to the CEO Marko Kobal and co-founder Sasa Coh, bitcoin worth $64 million USD was stolen, although users have pointed to a bitcoin wallet which holds 4,736.42 bitcoins, equivalent to $67 million.[63][64]
Cryptocurrency is also used in controversial settings in the form of online black markets, such as Silk Road. The original Silk Road was shut down in October 2013 and there have been two more versions in use since then; the current version being Silk Road 3.0. The successful format of Silk Road has been widely used in online dark markets, which has led to a subsequent decentralization of the online dark market. In the year following the initial shutdown of Silk Road, the number of prominent dark markets increased from four to twelve, while the amount of drug listings increased from 18,000 to 32,000.
Darknet markets present growing challenges in regard to legality. Bitcoins and other forms of cryptocurrency used in dark markets are not clearly or legally classified in almost all parts of the world. In the U.S., bitcoins are labelled as "virtual assets". This type of ambiguous classification puts mounting pressure on law enforcement agencies around the world to adapt to the shifting drug trade of dark markets.
Since most darknet markets run through Tor, they can be found with relative ease on public domains. This means that their addresses can be found, as well as customer reviews and open forums pertaining to the drugs being sold on the market, all without incriminating any form of user. This kind of anonymity enables users on both sides of dark markets to escape the reaches of law enforcement. The result is that law enforcement adheres to a campaign of singling out individual markets and drug dealers to cut down supply. However, dealers and suppliers are able to stay one step ahead of law enforcement, who cannot keep up with the rapidly expanding and anonymous marketplaces of dark markets collect from wikipedia.