The legal status of cryptocurrencies varies substantially from country to country and is still undefined or changing in many of them. While some countries have explicitly allowed their use and trade,[51] others have banned or restricted it. According to the Library of Congress, an "absolute ban" on trading or using cryptocurrencies applies in eight countries: Algeria, Bolivia, Egypt, Iraq, Morocco, Nepal, Pakistan, and the United Arab Emirates. An "implicit ban" applies in another 15 countries, which include Bahrain, Bangladesh, China, Colombia, the Dominican Republic, Indonesia, Iran, Kuwait, Lesotho, Lithuania, Macau, Oman, Qatar, Saudi Arabia and Taiwan.[52] In the United States and Canada, state and provincial securities regulators, coordinated through the North American Securities Administrators Association, are investigating "bitcoin scams" and ICOs in 40 jurisdictions.[53] 


比特币与莱特币都采用了区块链技术,且都有51%攻击的问题。它们采用区块链技术,所有历史记录按照时间先后顺序,打包成一个个单独的区块,再把这些单独的区块链接在一起形成一个总账本 [5]  。这些区块内除了包含交易记录外,还包含新发行的莱特币和交易的手续费,这两笔钱支付给挖矿的矿工作为酬劳。无论谁挖到该区块,那么该区块内含有的新发行的莱特币和交易的手续费这两笔钱都归挖到者,以鼓励矿工积极参与结算。区块链技术容易产生51%攻击的问题:无论任何组织甚至个人,只要掌控某一种基于区块链原理的虚拟货币的全部运算能力的51%,这个人或组织就能够任意操纵该虚拟货币的所有交易。如果区块链只认运算能力最大者,谁的运算能力最大,谁就能抢到下一个区块,如果某个个人或组织掌控了全部运算能力的51%,那就意味着没人比他运算能力更强,故而他就可以随意操纵。所以,对于基于区块链原理的虚拟货币,参与挖矿的越多就越健壮,运算能力越分散就越健壮;挖坑者越少越脆弱,运算能力越集中就越脆弱,矿池越集中也就越脆弱 [1]  。
A lot of people have made fortunes by mining Bitcoins. Back in the days, you could make substantial profits from mining using just your computer, or even a powerful enough laptop. These days, Bitcoin mining can only become profitable if you’re willing to invest in an industrial-grade mining hardware. This, of course, incurs huge electricity bills on top of the price of all the necessary equipment.


In January 2015, the company received a US$75 million investment, led by Draper Fisher Jurvetson, the New York Stock Exchange, USAA, and several banks.[20] Later in January, the company launched a U.S.-based bitcoin exchange for professional traders called Coinbase Exchange.[21] Coinbase began to offer services in Canada in 2015,[22] but in July 2016, Coinbase announced it would halt services in August after the closure of their Canadian online payments service provider Vogogo.[citation needed]

Hey to all. Since around 2 months, I am with 99bitcoins reading and getting info and I am very happy here, thanks for a good site. For my bad luck I did not check here for a review of coinbase, I would have save a lot of worthless time. To tell the truth, I hope there is a internet god out there and shut them down. I did not know about their support in US, but as I read the first reviews here, it seems they make themselves a pretty bad place there too. I am located in the D.R.,… Read more »


According to PricewaterhouseCoopers, four of the 10 biggest proposed initial coin offerings have used Switzerland as a base, where they are frequently registered as non-profit foundations. The Swiss regulatory agency FINMA stated that it would take a "balanced approach" to ICO projects and would allow "legitimate innovators to navigate the regulatory landscape and so launch their projects in a way consistent with national laws protecting investors and the integrity of the financial system." In response to numerous requests by industry representatives, a legislative ICO working group began to issue legal guidelines in 2018, which are intended to remove uncertainty from cryptocurrency offerings and to establish sustainable business practices.[50]


“While it’s still fairly new and unstable relative to the gold standard, cryptocurrency is definitely gaining traction and will most certainly have more normalized uses in the next few years. Right now, in particular, it’s increasing in popularity with the post-election market uncertainty. The key will be in making it easy for large-scale adoption (as with anything involving crypto) including developing safeguards and protections for buyers/investors. I expect that within two years, we’ll be in a place where people can shove their money under the virtual mattress through cryptocurrency, and they’ll know that wherever they go, that money will be there.” – Sarah Granger, Author, and Speaker. 


But while cryptocurrencies are more used for payment, its use as a means of speculation and a store of value dwarfs the payment aspects. Cryptocurrencies gave birth to an incredibly dynamic, fast-growing market for investors and speculators. Exchanges like Okcoin, Poloniex or shapeshift enables the trade of hundreds of cryptocurrencies. Their daily trade volume exceeds that of major European stock exchanges.


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.[70]
2) Pseudonymous: Neither transactions nor accounts are connected to real-world identities. You receive Bitcoins on so-called addresses, which are randomly seeming chains of around 30 characters. While it is usually possible to analyze the transaction flow, it is not necessarily possible to connect the real world identity of users with those addresses.