Actually almost all of your transaction is traceable in bitcoin. The only thing that they cannot do is to retrieve their lost coin if someone scam them using beautiful words. That is the only problem if the currency that you have is decentralized. No government is involved and you cannot complain if something happens to your money whether it is stolen or sent to the wrong address.
You can actually complain to the authorities if your bitcoin is stolen from you, but in many countries many do not even know what is bitcoin and how valuable it is, second most police departments do not have the tools to deal with crimes over the Internet that can be difficult to track, third the people that steal cryptocurrencies probably have experience trying to hide their tracks so it will be difficult to identify them, fourth and even if you can follow how those coins move most likely they will use a bitcoin mixer and you will lose their track.
And finally those hackers can be everywhere around the world, so if you only lost a small amount the authorities may not even investigate the case as it is not worth the effort for them.