Illiquidity. This is mostly moot due to Bitcoin’s $47 market cap but it still makes users sweat. It’s highly unlikely that Bitcoin’s price would plummet and you’d be unable to take action, but it’s still unsettling.  As more investors invest, however, illiquidity becomes a negligible risk, as there will likely always be a buyer for Bitcoins waiting.
What bitcoin miners actually do could be better described as competitive bookkeeping. Miners build and maintain a gigantic public ledger containing a record of every bitcoin transaction in history. Every time somebody wants to send bitcoins to somebody else, the transfer has to be validated by miners: They check the ledger to make sure the sender isn’t transferring money she doesn’t have. If the transfer checks out, miners add it to the ledger. Finally, to protect that ledger from getting hacked, miners seal it behind layers and layers of computational work—too much for a would-be fraudster to possibly complete.
Generally speaking, every bitcoin miner has a copy of the entire block chain on her computer. If she shuts her computer down and stops mining for a while, when she starts back up, her machine will send a message to other miners requesting the blocks that were created in her absence. No one person or computer has responsibility for these block chain updates; no miner has special status. The updates, like the authentication of new blocks, are provided by the network of bitcoin miners at large.

More fundamentally, miners argue that the current boom is simply the first rough step to a much larger technological shift that the basin would do well to get into early on. “What you can actually do with the technology, we’re only beginning to discover,” Salcido says. “But the technology requires a platform.” And, he says, as the world discovers what the blockchain can do, the global economy will increasingly depend on regions, like the basin, with the natural resources to run that platform as cheaply as possible.
About a year and a half after the network started, it was discovered that high end graphics cards were much more efficient at bitcoin mining and the landscape changed. CPU bitcoin mining gave way to the GPU (Graphical Processing Unit). The massively parallel nature of some GPUs allowed for a 50x to 100x increase in bitcoin mining power while using far less power per unit of work.
A specific problem that an internet payment system must solve is double-spending, whereby a user pays the same coin to two or more different recipients. An example of such a problem would be if Eve sent a bitcoin to Alice and later sent the same bitcoin to Bob. The bitcoin network guards against double-spending by recording all bitcoin transfers in a ledger (the blockchain) that is visible to all users, and ensuring for all transferred bitcoins that they haven't been previously spent.[14]:4

Mining is a record-keeping service done through the use of computer processing power.[e] Miners keep the blockchain consistent, complete, and unalterable by repeatedly grouping newly broadcast transactions into a block, which is then broadcast to the network and verified by recipient nodes.[64] Each block contains a SHA-256 cryptographic hash of the previous block,[64] thus linking it to the previous block and giving the blockchain its name.[3]:ch. 7[64]

Several news outlets have asserted that the popularity of bitcoins hinges on the ability to use them to purchase illegal goods.[128][224] Nobel-prize winning economist Joseph Stiglitz says that bitcoin's anonymity encourages money laundering and other crimes, "If you open up a hole like bitcoin, then all the nefarious activity will go through that hole, and no government can allow that." He's also said that if "you regulate it so you couldn’t engage in money laundering and all these other [crimes], there will be no demand for Bitcoin. By regulating the abuses, you are going to regulate it out of existence. It exists because of the abuses."[225][226]
Still, even supporters acknowledge that that glorious future is going to use a lot of electricity. It’s true that many of the more alarming claims—for example, that by 2020, bitcoin mining will consume “as much electricity as the entire world does today,” as the environmental website Grist recently suggested—are ridiculous: Even if the current bitcoin load grew a hundredfold, it would still represent less than 2 percent of total global power consumption. (And for comparison, even the high-end estimates of bitcoin’s total current power consumption are still less than 6 percent of the power consumed by the world’s banking sector.) But the fact remains that bitcoin takes an astonishing amount of power. By one estimate, the power now needed to mine a single coin would run the average household for 10 days.

Because of bitcoin's decentralized nature and its trading on online exchanges located in many countries, regulation of bitcoin has been difficult. However, the use of bitcoin can be criminalized, and shutting down exchanges and the peer-to-peer economy in a given country would constitute a de facto ban.[164] The legal status of bitcoin varies substantially from country to country and is still undefined or changing in many of them. Regulations and bans that apply to bitcoin probably extend to similar cryptocurrency systems.[165]

Illiquidity. This is mostly moot due to Bitcoin’s $47 market cap but it still makes users sweat. It’s highly unlikely that Bitcoin’s price would plummet and you’d be unable to take action, but it’s still unsettling.  As more investors invest, however, illiquidity becomes a negligible risk, as there will likely always be a buyer for Bitcoins waiting.
It is well known and recognised throughout the land, that the opposition to BREXIT is coming from those who are aligned together in various forms. Some are OPEN BORDERS AND MASS IMMIGRATION, others are GREEDY BIG BUSINESS IDENTITIES, wanting masses of cheap labour to compete with China and India etc--etc-. Others are TRAITORS wanting to disband the national identity of the British nation. The FASCIST leaning EU wants to remove Sovereign nations and turn them into GEOGRAPHIC AREA'S on a Brussels Empire Map. And yet again, there are the brain washed Students from third rate socialist universities ( LSE ), student unions trying to attack our heritage, and being allowed to do so by weak and unfit for purpose University Vice Chancellors. But thank god they are still in a small minority, probably all those who attended the Socialist Marxist uprising in Londonistan yesterday, were the bulk ( about 90%) of the Remainers who hate the democratic result of our referendum. But there are more than 20 million totally opposed to the EU, and we will LEAVE THE EU
The bitcoin network is a peer-to-peer payment network that operates on a cryptographic protocol. Users send and receive bitcoins, the units of currency, by broadcasting digitally signed messages to the network using bitcoin cryptocurrency wallet software. Transactions are recorded into a distributed, replicated public database known as the blockchain, with consensus achieved by a proof-of-work system called mining. Satoshi Nakamoto, the designer of bitcoin claimed that design and coding of bitcoin began in 2007. The project was released in 2009 as open source software.
All of which leaves the basin’s utilities caught between a skeptical public and a voracious, energy-intense new sector that, as Bolz puts it, is “looking at us in a predatory sense.” Indeed, every utility executive knows that to reject an application for a load, even one load so large as to require new transmission lines or out-of-area imports, is to invite a major legal fight. “If you can afford 100 megawatts,” Bolz says, “you can afford a lot of attorneys.”
But here, Carlson and his fellow would-be crypto tycoons confronted the bizarre, engineered obstinacy of bitcoin, which is designed to make life harder for miners as time goes by. For one, the currency’s mysterious creator (or creators), known as “Satoshi Nakamoto,” programmed the network to periodically—every 210,000 blocks, or once every four years or so—halve the number of bitcoins rewarded for each mined block. The first drop, from 50 coins to 25, came on November 28, 2012, which the faithful call “Halving Day.” (It has since halved again, to 12.5, and is expected to drop to 6.25 in June 2020.)

No one knows. Not conclusively, at any rate. Satoshi Nakamoto is the name associated with the person or group of people who released the original Bitcoin white paper in 2008 and worked on the original Bitcoin software that was released in 2009. The Bitcoin protocol requires users to enter a birthday upon signup, and we know that an individual named Satoshi Nakamoto registered and put down April 5 as a birth date. And that's about it.

On 1 August 2017, a hard fork of bitcoin was created, known as Bitcoin Cash.[103] Bitcoin Cash has a larger block size limit and had an identical blockchain at the time of fork. On 24 October 2017 another hard fork, Bitcoin Gold, was created. Bitcoin Gold changes the proof-of-work algorithm used in mining, as the developers felt that mining had become too specialized.[104]
Nakamoto is estimated to have mined one million bitcoins[26] before disappearing in 2010, when he handed the network alert key and control of the code repository over to Gavin Andresen. Andresen later became lead developer at the Bitcoin Foundation.[27][28] Andresen then sought to decentralize control. This left opportunity for controversy to develop over the future development path of bitcoin.[29][28]