Here are my edits to the rest of the FAQ:
Isn't Bitcoin mining a waste of energy?
Spending energy on securing and operating [to secure and operate] a payment system is hardly a waste. Like any other [payment] service, the use of Bitcoin is implying [entails] processing costs that are covered by the usefulness of the services offered. Services necessary for the operation of currently widespread monetary systems, such as banks and credit card companies[, credit cards, and armored vehicles], also spend [use] a lot of energy. So does any goods or services people are using or buying every day. However as opposed to [Although unlike] Bitcoin, this global [their total] energy consumption is not transparent and cannot be [easily] measured publicly.
Bitcoin mining has been designed to become more optimized over time with specialized hardware using [consuming] less energy[,] consumption and the operating costs of mining should continue to be proportional to the demand. When Bitcoin mining becomes unprofitable, some miners choose [miners tend to] to stop their activities. [Furthermore, all energy expended mining is eventually transformed into heat, and the most profitable miners will be those who have put this heat to good use. An optimally efficient mining network is one that isn't actually consuming any extra energy than would otherwise be consumed if no Bitcoin mining were taking place. While this is an ideal, the economics of mining are such that miners individually strive toward it.]
How does mining help secure Bitcoin?
Mining creates the equivalence [equivalent] of a competitive lottery that makes it very difficult for anyone to consecutively add new blocks of transactions in [into] the block chain. This allows to protect [protects] the neutrality of the network by preventing any individual to gain [from gaining] the power to block certain transactions. This also prevents any individual to replace [from replacing] parts of the block chain to roll back their own spends, which could be used to defraud other users. Additionally, mining [Mining] makes it exponentially difficult to reverse previous transactions because it would require to rewrite [a past transaction by requiring the rewriting of] all blocks following this transaction.
What do I need to start mining?
In the early days, anyone could find new blocks using standard computers['] CPUs. As more and more people started mining, the difficulty of finding new blocks has greatly increased to the point where the only cost-effective method of mining is using specialized hardware (ASICs). You can visit BitcoinMining.com for more information.
Security
Is Bitcoin secure?
The Bitcoin technology - the protocol and the cryptography - has a strong security track record[,] and the Bitcoin network is probably the biggest distributed computing project in the world. Bitcoin's vulnerability is in user error. Bitcoin wallet files that store the necessary private keys can be accidentally deleted, lost or stolen. This is pretty similar to physical cash in a computer or mobile. Fortunately, users can employ security practices to protect their money or use service providers that offer good levels of security and insurance [against theft or loss]. Bitcoins are not covered by insurance schemes or depositor insurance like the FDIC, but users' wallets could be with a service provider that offers that provision. Note: I just deleted this sentence because it just repeated what was said in the previous sentence, and it introduced confusion with the mention of deposit insurance, a solution to a much different problem than risk of theft or loss.
Hasn't Bitcoin been hacked in the past?
The Bitcoin protocol in itself has never suffered from a security breach and is still working great after [more than four] years, which is a fairly good indication that the concept is well designed. However, security flaws have been found and fixed over time in various software implementations. Like any other form of software, the security of Bitcoin software depends on the speed with which problems are found and fixed. The more such issues are discovered, the more Bitcoin is gaining maturity.
There is [are] often misconceptions about thefts and security breaches that happened on diverse exchanges and businesses. Although these events are unfortunate, in [during] none of them [has] Bitcoin has been hacked, [-] just like a bank being robbed doesn't mean that the dollar is compromised. However it is true that a complete set of good practices and intuitive security solutions need [needs] to be developped [developed] around Bitcoin to help [give] users having a better control and protection of their money[,] and continue to reduce the general risk of theft and loss. Over the course of the last [few] years, such security features [have quickly] developed at a fast rate like [, such as] wallet encryption, offline wallets, multi-signature [transactions] and hardware wallets.
Could users collude against Bitcoin?
It isn't possible to change the Bitcoin protocol with a majority of users or miners. Any miner that doesn't comply with the protocol immediately generates a chain fork[,] as the rest of the network [- non-mining nodes included -] is rejecting [rejects] blocks from these miners [this miner] , including all Bitcoin nodes that are not mining. As per the current specification, no double spending is possible on the same block chain[,] nor [and neither is] spending bitcoins without a valid signature. Consequently, it is not possible to generate uncontrolled amounts of bitcoins out of thin air, spend other users['] funds, corrupt the network or anything similar.
However, a majority of miners could arbirarily choose to block or reverse targeted recent transactions. This could be used for censorship purposes or to defraud targeted [particular] merchants. But this can also be used for legitimate purposes, like applying a collaborative emergency action to help fixing [fix] a problem with the network like the march 2013 chain fork[.]
Is Bitcoin vulnerable to quantum computing?
Yes, and so are all systems relying on cryptography in general[,] including current banking systems. However, quantum computers don't yet exist and probably won't for a while. In the event that quantum computing could be an imminent threat to Bitcoin, the protocol could be upgraded to use new algorithms. Given the importance that this update would have, it can be safely expected that it would be highly reviewed by developers and adopted by all Bitcoin users.
Can't Bitcoin be cracked or shutdown?
Bitcoin is likely to survive almost anything. The real question is to know where it will [where will it] prosper. Bitcoin has been designed to be a very resilient technology in order to be reliable as a global financial tool. The way it works is very similar to other decentralized networks such as the Internet. No individual or developer have [has] control over Bitcoin[,] and as long as some users and miners remain, the network will continue existing. This high level of resiliency and redundancy is unmatched in the payments space and represents an important breakthrough for the protection of financial systems.
Even though technical failures are possible, Bitcoin has demonstrated its ability to withstand various forms of attacks for years[,] and the discovery of new technical issues would likely only lead to further improvements. Bitcoin use could however be made difficult by restrictive regulations, in which case it would be hard to determine what percentage of users would keep using the technology. A government that chooses to make Bitcoin illegal would prevent many domestic businesses and markets from developing, shifting innovation to other countries.