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, 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. 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.
Coinbase is probably the easiest and safest way to purchase bitcoins in the U.S. Unlike BitStamp, Coinbase is not an exchange. They act as a counter-party to all customer trades, you buy or sell your bitcoins directly to Coinbase. The buy/sell fee is 1% on top of the buy/sell spread. The bid/ask is usually close to BitStamp where the firm gets its liquidity from. For example, the current bid is at $635.48 and the current ask is $638.07. In addition to this, the firm has daily limits on the amount of bitcoins bought/sold. These limits are not applied on the individual level. Basically Coinbase has a set amount of bitcoins that it is willing to buy or sell every day. During times or high volatility, users may not be able to buy/sell bitcoins until Coinbase decides to ‘’refill’’ their stock. Here’s a good explanation on this issue from their Customer Support:
On 21 November 2017, the Tether cryptocurrency announced they were hacked, losing $31 million in USDT 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.
For us non-miners, getting Bitcoin is now easier than it was a year ago. Now, one only needs to be in a right country to purchase and sell Bitcoins, where exchanges legally act as intermediaries for currency transactions — something that also protects your funds from being mismanaged by external and internal attacks. These exchanges instantly convert your Bitcoin into USD or other fiat currency, and based on the price fluctuations between these two, one can simultaneously sell and purchase their holdings and make good profits — a process we know as arbitrage (explained further below)
Bitcoins are mined with powerful computer hardware and software. A maximum of 21 million Bitcoin will be available, after which no further bitcoins will be produced. The algorithm which governs the production of Bitcoin limits the quantity that will be produced, and the rate at which they will be produced. It is a finite commodity – there is a fixed amount, and that ensures that greater demand will always prop up the price. In this way, it is similar to other finite commodities such as crude oil, silver, or gold.