Cryptocurrency is evolving very quickly, along with all the other technology that surrounds it, such as blockchain and the devices used to do those transactions. For example, these days, you can see a lot of transactions being done on a cell phone. Often, this will be encrypted on very sophisticated devices that are difficult for all law enforcement, not just the CRA. They can have a hard time cracking those devices in order to get access to the information inside. Obviously, we do this with warrants issued by the courts, but it can remain difficult, given how the technology is progressing.
We have the best tools, but the technology is progressing so quickly that it can be difficult to investigate sometimes.