Some types of customers may be at a higher risk. They can be judged, and there can be guidelines and what not as to what type of customers.... A lot will have to do, for example, with the type of business they're in, the size of the transactions they're doing, or country of origin. All these factors can be judged in terms of whether or not this is a customer who presents a high risk of being involved in money laundering transactions.
For example, I presume that if you found a customer whose business was exporting ether to Colombia, you might think they might be a bit of a high-risk customer. You can therefore tailor monitoring. You can get additional customer due diligence on that kind of customer. On the other hand, if your next-door neighbour whom you've known for thirty years comes to open an account with you, then you might consider them to be somewhat of a lower-risk customer and want to put lower kinds of customer due diligence obligations in that case.