Many litecoin investors followed the wrong herd last December when its founder Charlie Lee sold all of his shares in the company to avoid a conflict of interest. This should have indicated to investors that the price would not hold and would decline, Spatafora says. Instead of selling, many crypto investors bought more litecoin "like idiots when it was not sustainable," he says.
Cryptocurrencies are a potential tool to evade economic sanctions for example against Russia, Iran, or Venezuela. In April 2018, Russian and Iranian economic representatives met to discuss how to bypass the global SWIFT system through decentralized blockchain technology.[56] Russia also secretly supported Venezuela with the creation of the petro (El Petro), a national cryptocurrency initiated by the Maduro government to obtain valuable oil revenues by circumventing US sanctions.
Now imagine that I pose the "guess what number I'm thinking of" question, but I'm not asking just three friends, and I'm not thinking of a number between 1 and 100. Rather, I'm asking millions of would-be miners and I'm thinking of a 64-digit hexadecimal number. Now you see that it's going to be extremely hard to guess the right answer. (See also: What is Bitcoin Mining?)
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.”

In May 2018, Bitcoin Gold (and two other cryptocurrencies) were hit by a successful 51% hashing attack by an unknown actor, in which exchanges lost estimated $18m.[72] In June 2018, Korean exchange Coinrail was hacked, losing US$37 million worth of altcoin. Fear surrounding the hack was blamed for a $42 billion cryptocurrency market selloff.[73] On 9 July 2018 the exchange Bancor had $23.5 million in cryptocurrency stolen.[74]

The Ethereum Platform rests on open-source software, and there is a risk that the Ethereum Stiftung or the Ethereum Team, or other third parties not directly affiliated with the Stiftung Ethereum, may introduce weaknesses or bugs into the core infrastructural elements of the Ethereum Platform causing the system to lose ETH stored in one or more User accounts or other accounts or lose sums of other valued tokens issued on the Ethereum Platform.