I would argue that Bitcoin can be anonymous and having a Bitcoin wallet with Bitcoins in, depending on your method of acquiring them, will not give away your real world identity as no ID is required to set up a wallet, buy Bitcoins or use mixing and tumbling services. So it is not true that you have to provide ID to buy or sell Bitcoins of any amount. Localbitcoins.com for example allows you to meet up in person to exchange cash for Bitcoins and you only need to provide an email address to set up accounts enabling buying or selling of very large amounts £50k+. I have never provided ID to complete Bitcoin transactions even with real world retailers, just a delivery address. While Bitcoins can be traced through multiple wallets and transactions via the public blockchain this in itself does not provide any links to personally identifiable information. It took over 7 years of investigation to get the Silk Road operators (if I remember correctly from the documentary 'Deep Web') and they still only prosecuted a tiny number of them and these were seriously high volume Bitcoin users. I am a bitcoin miner and there is no way any of my mined Bitcoins can be traced back to my real world identity, unless as your article stated, I purchase goods or services that require a delivery address, then at that point a link could be made. This information would need to be obtained outside the blockchain through coordinating retailers records, then various other agencies to link the address to me and only government agencies would realistically have this capability. So Bitcoin can be 100% anonymous if you are extremely careful about your internet security and tumble coins directly before making any real world purchases, using dead drop addresses and don't access your Bitcoin wallet from your home internet or a personal computer potentially linking you Bitcoins to your IP address or a personal computer with personally identifiable information on it. Also don't store Bitcoins on a personal computer for the same reasons, cold (off line) storage is the safest and most private with a seed or private key to reinstate it when needed and never use your mobile devices to do anything Bitcoin related. However this level of security would only be used by serious criminals and the average users privacy would not be compromised as the resources it takes to identify you this way is only worth it, if you are involved in serious crime and known to law enforcement who are targeting you. I also want to point out that criminal activity is no longer the biggest use of Bitcoins, not that I think your article claimed this but it is a widely held belief, and that any serious criminal activities still use the corrupt financial and banking systems. ISIS receiving £2 million per day in illegal oil revenues for example is not done through the Bitcoin network. I say this as it harms Bitcoins reputation to present it as predominantly a way to fund serious criminal activity because this isn't a true reflection of the diverse uses it now has.