Ethereum has recently created a new standard called the ERC721 token for tracking unique digital assets. One of the biggest use cases currently for such tokens is digital collectibles, as the infrastructure allows for people to prove ownership of scarce digital goods. Many games are currently being built using this technology, such as the overnight hit CryptoKitties, a game where you can collect and breed digital cats.
David Golumbia says that the ideas influencing bitcoin advocates emerge from right-wing extremist movements such as the Liberty Lobby and the John Birch Society and their anti-Central Bank rhetoric, or, more recently, Ron Paul and Tea Party-style libertarianism. Steve Bannon, who owns a "good stake" in bitcoin, considers it to be "disruptive populism. It takes control back from central authorities. It's revolutionary."
The proof-of-work system, alongside the chaining of blocks, makes modifications of the blockchain extremely hard, as an attacker must modify all subsequent blocks in order for the modifications of one block to be accepted. As new blocks are mined all the time, the difficulty of modifying a block increases as time passes and the number of subsequent blocks (also called confirmations of the given block) increases.
In March 2013 the blockchain temporarily split into two independent chains with different rules due to a bug in version 0.8 of the bitcoin software. The two blockchains operated simultaneously for six hours, each with its own version of the transaction history from the moment of the split. Normal operation was restored when the majority of the network downgraded to version 0.7 of the bitcoin software, selecting the backward compatible version of the blockchain. As a result, this blockchain became the longest chain and could be accepted by all participants, regardless of their bitcoin software version. During the split, the Mt. Gox exchange briefly halted bitcoin deposits and the price dropped by 23% to $37 before recovering to previous level of approximately $48 in the following hours. The US Financial Crimes Enforcement Network (FinCEN) established regulatory guidelines for "decentralized virtual currencies" such as bitcoin, classifying American bitcoin miners who sell their generated bitcoins as Money Service Businesses (MSBs), that are subject to registration or other legal obligations. In April, exchanges BitInstant and Mt. Gox experienced processing delays due to insufficient capacity resulting in the bitcoin price dropping from $266 to $76 before returning to $160 within six hours. The bitcoin price rose to $259 on 10 April, but then crashed by 83% to $45 over the next three days. On 15 May 2013, US authorities seized accounts associated with Mt. Gox after discovering it had not registered as a money transmitter with FinCEN in the US. On 23 June 2013, the US Drug Enforcement Administration listed ₿11.02 as a seized asset in a United States Department of Justice seizure notice pursuant to 21 U.S.C. § 881.[better source needed] This marked the first time a government agency had seized bitcoin. The FBI seized about ₿30,000 in October 2013 from the dark web website Silk Road during the arrest of Ross William Ulbricht. These bitcoins were sold at blind auction by the United States Marshals Service to venture capital investor Tim Draper. Bitcoin's price rose to $755 on 19 November and crashed by 50% to $378 the same day. On 30 November 2013 the price reached $1,163 before starting a long-term crash, declining by 87% to $152 in January 2015. On 5 December 2013, the People's Bank of China prohibited Chinese financial institutions from using bitcoins. After the announcement, the value of bitcoins dropped, and Baidu no longer accepted bitcoins for certain services. Buying real-world goods with any virtual currency had been illegal in China since at least 2009.