Authorities Can Relax - Bitcoin is Not Anonymous
There is no question that cryptocurrencies may help to facilitate criminal activities such as terrorism, money laundering, and cybercrime. There is also no question that cash has been helping to facilitate the same criminal activities for much longer, and quite successfully.
And finally, there is no question that the appropriate authorities should be investigating and protecting the public from many of these crimes. The good news is that Bitcoin and other public blockchains should be viewed as a tool for authorities to collect and verify evidence, because unlike cash, there is a transparent, public, and immutable record of every single transaction on the Bitcoin blockchain. You can view them here.
Blockchain AML companies have popped up in the last few years to help institutions get their arms around blockchain investigation. Companies like Chainalysis and Elliptic are providing professional AML/KYC management tools for blockchain-based companies and money transmitters.
For more information, also see Deloitte's paper on Blockchain Applications in Banking.