Up until July 2017, bitcoin users maintained a common set of rules for the cryptocurrency. On 1 August 2017 bitcoin split into two derivative digital currencies, the bitcoin (BTC) chain with 1 MB blocksize limit and the Bitcoin Cash (BCH) chain with 8 MB blocksize limit. The split has been called the "Bitcoin Cash hard fork". On 6 December 2017 the software marketplace Steam announced that it would no longer accept bitcoin as payment for its products, citing slow transactions speeds, price volatility, and high fees for transactions. On 22 January 2018, South Korea brought in a regulation that requires all the bitcoin traders to reveal their identity, thus putting a ban on anonymous trading of bitcoins. On 24 January 2018, the online payment firm Stripe announced that it would phase out its support for bitcoin payments by late April 2018, citing declining demand, rising fees and longer transaction times as the reasons. As of September 2019, there were 5,457 Bitcoin ATMs worldwide. In August of that year, the countries with highest number of Bitcoin ATMs were the United States, Canada, the United Kingdom, Austria, and Spain. Among the factors which may have contributed to this rise were the European sovereign-debt crisis particularly the 2012–2013 Cypriot financial crisis statements by FinCEN improving the currency's legal standing and rising media and Internet interest. Until 2013, almost all market with bitcoins were in United States dollars (US$). As the market valuation of the total stock of bitcoins approached US$1 billion, some commentators called bitcoin prices a bubble. In early April 2013, the price per bitcoin dropped from $266 to around $50 and then rose to around $100. Over two weeks starting late June 2013 the price dropped steadily to $70. The price began to recover, peaking once again on 1 October at $140. On 2 October, The Silk Road was seized by the FBI. This seizure caused a flash crash to $110. The price quickly rebounded, returning to $200 several weeks later. The latest run went from $200 on 3 November to $900 on 18 November. Bitcoin passed US$1,000 on 28 November 2013 at Mt. Gox. A fork referring to a blockchain is defined variously as a blockchain split into two paths forward, or as a change of protocol rules. Accidental forks on the bitcoin network regularly occur as part of the mining process. They happen when two miners find a block at a similar point in time. As a result, the network briefly forks. This fork is subsequently resolved by the software which automatically chooses the longest chain, thereby orphaning the extra blocks added to the shorter chain (that were dropped by the longer chain).