An SPF or single point failure occurs when such a scenario gets created. Compliance is yet another article to be taken care of, where two things are to be covered. The first is KYC process, which is more complex than others because it has to be integrated with an image upload that makes the system quite exposed and vulnerable to the hack threats and malware.
The second is accounting, which again is a big task to regulate and scrutinize because there are different cryptocurrencies on the exchange and one does not wish to change the mode of payment to any medium he does not use frequently.